Internet

Dictionary: In·ter·net   (ĭn'tər-nĕt')

An interconnected system of networks that connects computers around the world via the TCP/IP protocol.

A worldwide system of interconnected computer networks. The origins of the Internet can be traced to the creation of ARPANET (Advanced Research Projects Agency Network) as a network of computers under the auspices of the U.S. Department of Defense in 1969. Today, the Internet connects millions of computers around the world in a nonhierarchical manner unprecedented in the history of communications. The Internet is a product of the convergence of media, computers, and telecommunications. It is not merely a technological development but the product of social and political processes, involving both the academic world and the government (the Department of Defense). From its origins in a nonindustrial, noncorporate environment and in a purely scientific culture, it has quickly diffused into the world of commerce.

The Internet is a combination of several media technologies and an electronic version of newspapers, magazines, books, catalogs, bulletin boards, and much more. This versatility gives the Internet its power.

Technological features

The Internet 'Ls technological success depends on its principal communication tools, the Transmission Control Protocol (TCP) and the Internet Protocol (IP). They are referred to frequently as TCP/IP. A protocol is an agreed-upon set of conventions that defines the rules of communication. TCP breaks down and reassembles packets, whereas IP is responsible for ensuring that the packets are sent to the right destination.

Data travels across the Internet through several levels of networks until it reaches its destination. E-mail messages arrive at the mail server (similar to the local post office) from a remote personal computer connected by a modem, or a node on a local-area network. From the server, the messages pass through a router, a special-purpose computer ensuring that each message is sent to its correct destination. A message may pass through several networks to reach its destination. Each network has its own router that determines how best to move the message closer to its destination, taking into account the traffic on the network. A message passes from one network to the next, until it arrives at the destination network, from where it can be sent to the recipient, who has a mailbox on that network. See also Electronic mail; Local-area networks; Wide-area networks.

TCP/IP

TCP/IP is a set of protocols developed to allow cooperating computers to share resources across the networks. The TCP/IP establishes the standards and rules by which messages are sent through the networks. The most important traditional TCP/IP services are file transfer, remote login, and mail transfer.

The file transfer protocol (FTP) allows a user on any computer to get files from another computer, or to send files to another computer. Security is handled by requiring the user to specify a user name and password for the other computer.

The network terminal protocol (TELNET) allows a user to log in on any other computer on the network. The user starts a remote session by specifying a computer to connect to. From that time until the end of the session, anything the user types is sent to the other computer.

Mail transfer allows a user to send messages to users on other computers. Originally, people tended to use only one or two specific computers. They would maintain “mail files” on those machines. The computer mail system is simply a way for a user to add a message to another user's mail file.

Other services have also become important: resource sharing, diskless workstations, computer conferencing, transaction processing, security, multimedia access, and directory services.

TCP is responsible for breaking up the message into datagrams, reassembling the datagrams at the other end, resending anything that gets lost, and putting things back in the right order. IP is responsible for routing individual datagrams. The datagrams are individually identified by a unique sequence number to facilitate reassembly in the correct order. The whole process of transmission is done through the use of routers. Routing is the process by which two communication stations find and use the optimum path across any network of any complexity. Routers must support fragmentation, the ability to subdivide received information into smaller units where this is required to match the underlying network technology. Routers operate by recognizing that a particular network number relates to a specific area within the interconnected networks. They keep track of the numbers throughout the entire process.

Domain Name System

The addressing system on the Internet generates IP addresses, which are usually indicated by numbers such as 128.201.86.290. Since such numbers are difficult to remember, a user-friendly system has been created known as the Domain Name System (DNS). This system provides the mnemonic equivalent of a numeric IP address and further ensures that every site on the Internet has a unique address. For example, an Internet address might appear as crito.uci.edu. If this address is accessed through a Web browser, it is referred to as a URL (Uniform Resource Locator), and the full URL will appear as http://www.crito.uci.edu.

The Domain Name System divides the Internet into a series of component networks called domains that enable e-mail (and other files) to be sent across the entire Internet. Each site attached to the Internet belongs to one of the domains. Universities, for example, belong to the “edu” domain. Other domains are gov (government), com (commercial organizations), mil (military), net (network service providers), and org (nonprofit organizations).

World Wide Web

The World Wide Web (WWW) is based on technology called hypertext. The Web may be thought of as a very large subset of the Internet, consisting of hypertext and hypermedia documents. A hypertext document is a document that has a reference (or link) to another hypertext document, which may be on the same computer or in a different computer that may be located anywhere in the world. Hypermedia is a similar concept except that it provides links to graphic, sound, and video files in addition to text files.

In order for the Web to work, every client must be able to display every document from any server. This is accomplished by imposing a set of standards known as a protocol to govern the way that data are transmitted across the Web. Thus data travel from client to server and back through a protocol known as the HyperText Transfer Protocol (http). In order to access the documents that are transmitted through this protocol, a special program known as a browser is required, which browses the Web. See also World Wide Web.

Commerce on the Internet

Commerce on the Internet is known by a few other names, such as e-business, Etailing (electronic retailing), and e-commerce. The strengths of e-business depend on the strengths of the Internet. Internet commerce is divided into two major segments, business-to-business (B2B) and business-to-consumer (B2C). In each are some companies that have started their businesses on the Internet, and others that have existed previously and are now transitioning into the Internet world. Some products and services, such as books, compact disks (CDs), computer software, and airline tickets, seem to be particularly suited for online business.

(1) (Lower case "i" internet) A large network made up of a number of smaller networks.

(2) (Upper case "I" Internet) The global network of networks (see definition #1 above), composed of hundreds of millions of computers in more than 100 countries. Originally developed for the U.S. military, it became widely used for academic and commercial research, with access to unpublished data and journals on many subjects. Today, the "Net" is the world's largest source of information on every subject known to humankind and the world's largest mail-order catalog. By 2005, the Internet surpassed one billion users.

E-Mail Lit the Fuse

The Internet surged in growth in the mid-1990s, increasing a hundredfold in 1995 and 1996 alone. There were two reasons. Up to that point, the major online services, such as AOL and CompuServe, provided e-mail only to their own customers. As they began to reach out to Internet users by interfacing with the Internet's mail system, the Internet automatically took on the role of global switching center. An AOL member could, for the first time, send an e-mail message to a CompuServe member, and vice versa. The Internet's e-mail protocol glued the world together for messaging, and it became the e-mail standard for the world (see SMTP).

The Bomb Exploded with the Web

Secondly, with the advent of graphics-based Web browsers such as Mosaic and Netscape Navigator, and soon after, Microsoft's Internet Explorer, the World Wide Web took off. The Web became available to users with PCs and Macs rather than only scientists and hackers at Unix workstations. Delphi was the first proprietary online service to offer Web access, and all the rest followed. All of a sudden, Internet service providers (ISPs) rose out of the woodwork to offer access to everyone, and the Web grew exponentially. Network traffic using Web protocols became the majority of all Internet traffic (see HTTP and HTML).

Newsgroups

Although daily news and information is available on countless Web sites, long before the Web, information on myriad subjects was exchanged via Usenet (User Network) newsgroups. Still thriving, newsgroup articles can be selected and read directly from your Web browser. See Usenet.

Chat Rooms

Chat rooms provide another popular Internet service. Internet Relay Chat (IRC) offers multiuser text conferencing on diverse topics. Dozens of IRC servers provide hundreds of channels that anyone can log in to and participate in via the keyboard. See IRC.

The Original Internet

The Internet started in 1969 as the ARPAnet. Funded by the U.S. government, ARPAnet became a series of high-speed links between major supercomputer sites and educational and research institutions worldwide, although mostly in the U.S. A major part of its backbone was the National Science Foundation's NSFNet. Along the way, it became known as the "Internet" or simply "the Net." By the 1990s, so many networks had become part of it and so much traffic was not educational or pure research in nature that it became obvious that the Internet was on its way to becoming a commercial venture.

It Went Commercial in 1995

In 1995, the Internet was turned over to large commercial Internet providers (ISPs), such as MCI, Sprint and UUNET, which took responsibility for the backbones and have increasingly enhanced their capacities ever since. Regional ISPs link into these backbones to provide lines for their subscribers, and smaller ISPs hook either directly into the national backbones or into the regional ISPs.

The TCP/IP Protocol

Internet computers use the TCP/IP communications protocol. There are hundreds of millions of hosts on the Internet, a host being a server of any size that is always online via TCP/IP and providing e-mail or Web or some Internet-based service. The Internet is also connected to non-TCP/IP networks worldwide through gateways that convert TCP/IP into other protocols. See TCP/IP.

Internet Life Before the Web

Before the Web and graphics-based Web browsers, academicians and scientists accessed the Internet using command-driven Unix utilities. Some of these utilities are still widely used and are available for all platforms. For example, FTP (file transfer program) is used to upload and download files, and Telnet lets a user log in to an Internet host and run a program. See FTP, Telnet, Archie, Gopher and Veronica.

The Next Internet

Ironically, some of the original academic and scientific users of the Internet have developed their own Internet once again. Internet2 is a high-speed academic research network that was started in much the same fashion as the original Internet (see Internet2). See Web vs. Internet, World Wide Web, how to search the Web, intranet, NAP, hot topics and trends, IAB, information superhighway and online service.

Modest Beginnings

How the Internet Is Connected

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Public network of nearly 50,000 networks connecting millions of computers throughout the world. The Internet originally evolved from a U.S. Defense Department experimental network developed in the late 1960s and early 1970s, but since the mid-1990s it has transformed the way people communicate and do business. Anyone with access to a personal computer and a modem can become connected to the Internet and, within certain limits, can send and receive images and data just about anywhere. The Internet does not actually contain information but rather functions as the transport vehicle for information stored in the files or documents contained in the computers it connects. Providing an efficient way to find and share information, the Internet offers services such as e-mail, discussion groups, product information, research capabilities, new software, and the World Wide Web. It has become a viable advertising medium and is increasingly being factored into advertising budgets. In 1998, Internet advertising revenues were reported at $1.92 billion, surpassing reported revenues of outdoor advertising and positioning the Internet well within the role of traditional media outlets. In addition, the Internet technology has resulted in an increase in new types of businesses such as World Wide Web page designers, interactive advertising agencies, and companies that provide secure financial transaction systems. See also world wide web.

Immense collection of networks that are interconnected on a global basis providing services to the general public. These services include the transferring of files among computers, hypertext transfer protocol (HTTP) involving the reading and interpreting of hypertext files (web pages) that contain pictures and sounds, and operating computers from distant locations. Computers use telephone lines, optical fibers, and radio transmissions to connect networks thereby forming Internets. Thus, the Internet is really a super highway along which information travels to the electronic address of its destination computer. Along the way this information may pass through computer network to computer network several times before reaching its electronic address.

1. The Internet can be used to determine life insurance needs and compare costs and types of life insurance policies by referencing the following web sites: www.rightquote.com; www.quickquote.com; and www.accuquote.com

2. Similar analysis of health and disability insurance can be found at these web sites:

www.northcoast.com/unlimited/services_listing/greg_connors/gci.html; www.service.com/answers/health_insurance.html

3. For homeowners, renters, and automobile insurance, the following web sites may be referenced: www.insure.com; www.iiaa.iix.com; www.insuremarket.com

The Internet is a technology and electronic communication system such as the world has never seen before. In fact, some people have said that the Internet is the most important innovation since the development of the printing press.

History of the Internet

The Internet was created as a result of the Cold War. In the mid 1960s it became apparent that there was a need for a bomb-proof electronic communication system. A concept was devised to link computers by cable or wire throughout the country in a distributed system so that if some parts of the country were cut off from other parts, messages could still get through. In the beginning, only the federal government and a few universities were linked because the Internet was basically an emergency military communication system, operated by the Department of Defense's Advanced Research Project Agency (ARPA). The whole operation was referred to as ARPANET.

ARPA was linked to computers at a group of top research universities receiving ARPA funding. The first four universities connected to ARPANET were the University of California-Los Angeles, Stanford University, the University of California-Santa Barbara, and the University of Utah. Thus, the Internet was born. Because of a concept developed by Larry Roberts of ARPA and Glen Kleinrock at UCLA, called packet switching, the Internet was able to become a decentralized system, which would prevent large-scale destruction of any centralized system. The system allowed different types of computers from different manufacturers to send messages to one another. Computers merely transmitted information to one another in a standardized protocol packet. The addressing information in these packets told each computer in the chain where the packet was supposed to go.

As the Internet grew, more capability was added. A program called Telnet allowed remote users to run programs and computers at other sites. The File Transfer Protocol (FTP) allowed users to transfer data files and programs. Gopher programs, developed at the University of Minnesota and named after the university's mascot, allowed menu-driven access to data resources on the Internet. Search engines such as Archie and Wide Area Index Search (WAIS) gave users the ability to search the Internet's numerous libraries and indices. By the 1980s people at universities, research laboratories, private companies, and libraries were aided by a networking revolution. There were more than thirty thousand host computers and modems on the Internet. The fore-runner of the Internet was the Bitnet, which was a network of virtually every major university in the world. E-mail became routine and inexpensive, since the Internet is a parasite using the existing multibillion-dollar telephone networks of the world as its carriers.

In 1972 Ray Tomlinson invented network e-mail, which became possible with the FTP. With e-mail and FTP, the rate at which collaborative work could be conducted between researchers at participating computer science departments was greatly increased. Although it was not realized at the time, the Internet had begun. TCP (Transmission Control Protocol) breaks large amounts of data down into packets of a fixed size, sequentially numbers them to allow reassembly at the recipient's end, and transmits the packets over the Internet using the Internet protocol.

After the invention of e-mail, it wasn't long before mailing lists were invented. This was a technique by which an identical message could be sent automatically to large numbers of people. The Internet continues to grow. In fact, it is estimated that almost 65 million adults go online on the Internet in the United States every month. Presently, no one operates the Internet. Although there are entities that oversee the system, "no one is in charge." This allows for a free transfer and flow of information throughout the world.

In 1984 the National Science Foundation (NSF) developed NSFNET. Later NASA, the National Institutes of Health, and others became involved, and nodes on the Internet were divided into basic varieties that are still used today. The varieties are grouped by the six basic Internet domains of GOV, MIL, EDU, COM, ORG, and NET. The ARPANET itself formally expired in 1989, a victim of its own success, and the use of TCP/IP (Transfer Control Protocol/Internet Protocol) standards for computer networks is now global.

If Internet invention had stopped at this point, we would probably still be using the Internet primarily just for e-mail. However, in 1989 a second miracle occurred. Tim Berners-Lee, a software engineer at the CERN physics lab in Switzerland, developed a set of accepted protocols for the exchange of Internet information, and a consortium with users was formed—thus creating the World Wide Web, the standard language for encoding information. Hypertext Markup Language (HTML) was adopted. Berners-Lee proposed making the idea global to link all documents on the Internet using hypertext. This lets users jump from one document to another through highlighted words. Other web standards, such as URL (Universal Resource Language) addresses on the Web page and HTTP (Hypertext Transfer Protocol), are also Berners-Lee's inventions. Berners-Lee could have been exceedingly rich based on his invention, but he left the fortune-building to others because he "wanted to do the revolution right."

As a result of Berners-Lee's invention, in 1993 a group at the University of Illinois, headed by Mark Andreesen, wrote a graphical application called Mosaic to make use of the Web easier. The next year a few students from that group, including Andreesen, co-founded Netscape after they graduated in May and released the browser for the World Wide Web in November 1994. The World Wide Web is making the Internet easier to use and has brought two giant advantages. Until the Web, the Internet communicated text only, but the Web permits exchange of uncoded graphics, color-coded graphics, color photographs and designs, even video and sound; and it formats typed copy into flexible typographic pages. The Web also permits use of hyperlinks, whereby users can click on certain words or phrases and be shown links to other information or pictures that explain the key words or phrases. As a result of the World Wide Web and Web browsers, it became easy to find information on the Internet and the Web. Various search engines have been developed to index and retrieve this information.

Using the Internet

How does one use the Internet? First, one must have a computer with a connection to the outside world either by a modem connection, a fiber connection such as used in local cable television, or a wireless connection, which is becoming more important. The user is then connected to a system of linked computer networks that encircle the globe, facilitating a wide assortment of data communication services including e-mail, data and program file transfers, newsgroups and chatgroups, as well as graphic images, sound, and video of all kinds. One must choose the right tool to accomplish each task. Thus, one needs to understand the tools to travel this information superhighway.

The Internet is in cyberspace; think of it as a number of planets, each with a unique kind of data program or other type of information service. The only hitch is that each planet's communicating language is different, and one needs several communicating applications and tools. A person is responsible for selecting the proper software program or utility to access what he or she wants. Each program performs a specific task, ranging from providing basic connections, to accessing resources, to preparing e-mail. Common Internet tools include the following:

1. Connection and log-on software. This software provides access to logon to cyber-space. The software sets up the connections to the Internet. This software is usually provided by an Internet service provider.
2. Web browser. Web browsers are usually free. The most common Web browsers are Microsoft's Internet Explorer and Netscape's Navigator. These software programs can usually be downloaded free of charge; they also come with office suites such as Microsoft Office.
3. E-mail manager and editor. To communicate by e-mail users must have an e-mail manager and editor. This editor creates, sends, receives, stores, and organizes your e-mail. Again, many of these e-mail editors can be downloaded free from the Web. One of the most common editors is Eudora. However, office suites usually come with an e-mail manager as well.

A custom connect program starts the procedure for logging on to the Internet using TCP/IP. This is a set of standards and protocols for sharing data between computers and the Internet. Once the protocols have connected, a user must establish his or her identity and authorization to use the Internet services. The Internet service provider used has its own identity on the Internet, and this identity is known as a domain. Domain names, as mentioned previously, are all names listed to the right of the @ sign in the address with an extension such as .com or .edu. The computer then sends and receives data from a host computer over the Internet. A program such as Telnet breaks up the data into packets. The protocols specify how packets should be layered, or packaged. Different layers of packets address a variety of software and hardware needs to send information over different networks and communication links. After a user has properly logged on, he or she can begin using the Internet services.

After a user has completed an on-line work session, he or she must logoff the Internet and, depending on the circumstances, disconnect from the Internet service provider. If a user is using an educational service provider such as a college or other educational institution, he or she probably logs off but does not disconnect, since the service is a virtual service provided to many others at the terminal or computer. If one is using a private commercial service provider, one must be sure that a complete disconnection has been made between the computer and provider or one may still be paying fees.

The Internet has spawned an entirely whole new industry called electronic commerce or sometimes electronic business. Businesses sell to other businesses and to consumers on the Internet using secure Web sites. The current market value of U.S. companies with substantial Internet revenue via e-commerce exceeds $3 trillion and is growing annually. It is estimated that by 2003 over 88 percent of all businesses will derive some of their revenue from e-commerce. It has also been said that the growth of the Internet and e-commerce has been one of the main causes of the robust economy in the United States.

Thus, the Internet has been one of the most productive technologies in recent history. The Internet can transport information from nearly any place on the globe to nearly any other place in seconds. The Internet has changed people's notion of how fast things happen. People say now they "did it in Internet time," meaning something was done in a fraction of the traditional or expected amount of time. The Internet is becoming a major cause of time compression.

Future of the Internet

What does the future hold for the Internet? Predictions are that in the future nearly every Internet-connected device will communicate wirelessly. Low-power radio cells rather than fiber or copper wire, will connect and relay information. Before 2010, more than half of American homes will have at least one low power radio cell connected to Internet bandwidth. The future appears to hold a wireless Internet because of bandwidth problems with cable or wire.

The personal computer will continue to evolve, but there will be a lot of other Internet-smart appliances. Predictions are that there will be Internet wristwatches to match the person with the message. Televisions will, when prompted, record our favorite shows. Various kitchen appliances will start by Internet commands. The personal automobile will also be a mobile personal information store. Automobiles will have internal connectivity and easily carry a very large cache of favorite music, talk, interactive games, and pictures, while passengers will have the option of looking out the window at the real world or looking in the window of their in-car display. Like the explorers who discovered new continents, people are just beginning to discover the full impact of the Internet on information, space, and time.

Bibliography

Anderson, John. "Internet History and Perspective." www2.advisorworks.com. February 28, 2000.

Baylogic. "Net History and Statistics." www.baylogic.com. February 28, 2000.

Berners-Lee, Tim. (1996) "Passing up Fortune-Building 'To Do the Revolution Right'." Investor's Business Daily 13(43)(June 7):1-2.

Reidelbach, Dorothy. (1996). "The Amazing New World Wide Web." Planning for Higher Education 24 (Spring):1-6.

Ricart, Glenn. (2000). "Unofficial Technology Marvel of the Millennium." Educause Review January/February: 38-59.

Rochester, Jack B. (1996). Using Computers and Information. Indianapolis, IN: Macmillan.

[Article by: LLOYD W. BARTHOLOME]

The mother of all networks. First incarnated beginning in 1969 as the ARPANET, a U.S. Department of Defense research testbed. Though it has been widely believed that the goal was to develop a network architecture for military command-and-control that could survive disruptions up to and including nuclear war, this is a myth; in fact, ARPANET was conceived from the start as a way to get most economical use out of then-scarce large-computer resources. Robert Herzfeld, who was director of ARPA at the time, has been at some pains to debunk the “survive-a-nuclear-war” myth, but it seems unkillable.

As originally imagined, ARPANET's major use would have been to support what is now called remote login and more sophisticated forms of distributed computing, but the infant technology of electronic mail quickly grew to dominate actual usage. Universities, research labs and defense contractors early discovered the Internet's potential as a medium of communication between humans and linked up in steadily increasing numbers, connecting together a quirky mix of academics, techies, hippies, SF fans, hackers, and anarchists. The roots of this lexicon lie in those early years.

Over the next quarter-century the Internet evolved in many ways. The typical machine/OS combination moved from DEC PDP-10s and PDP-20s, running TOPS-10 and TOPS-20, to PDP-11s and VAXen and Suns running Unix, and in the 1990s to Unix on Intel microcomputers. The Internet's protocols grew more capable, most notably in the move from NCP/IP to TCP/IP in 1982 and the implementation of Domain Name Service in 1983. It was around this time that people began referring to the collection of interconnected networks with ARPANET at its core as “the Internet”.

The ARPANET had a fairly strict set of participation guidelines -- connected institutions had to be involved with a DOD-related research project. By the mid-80s, many of the organizations clamoring to join didn't fit this profile. In 1986, the National Science Foundation built NSFnet to open up access to its five regional supercomputing centers; NSFnet became the backbone of the Internet, replacing the original ARPANET pipes (which were formally shut down in 1990). Between 1990 and late 1994 the pieces of NSFnet were sold to major telecommunications companies until the Internet backbone had gone completely commercial.

That year, 1994, was also the year the mainstream culture discovered the Internet. Once again, the killer app was not the anticipated one — rather, what caught the public imagination was the hypertext and multimedia features of the World Wide Web. Subsequently the Internet has seen off its only serious challenger (the OSI protocol stack favored by European telecoms monopolies) and is in the process of absorbing into itself many of the proprietary networks built during the second wave of wide-area networking after 1980. By 1996 it had become a commonplace even in mainstream media to predict that a globally-extended Internet would become the key unifying communications technology of the next century. See also the network.

The Internet allows multimedia documents to be moved between any two computers, using an "internetwork" of relaying computers. Multimedia documents can be found by those seeking information using a web browser to "pull" information off the "World Wide Web," or using an e-mail system to "push" information to those currently uninterested or unaware of an issue.

The Internet has been called an "engine of empowerment" that creates healthy "virtual communities." Others, however, say it increases may social and health-related problems, including individual isolation and risky sexual practices by fragmenting relationships and by increasing the anonymous distribution and viewing of pornographic material. These seemingly contradictory outcomes can be reconciled in understanding that the Internet, like any communications technology, amplifies the intentions of its users. It amplifies these intentions by primarily increasing the "reach" of both the sender and receiver, who often share a common interest. As a result, its use may only increase the sharing of information that reinforces and amplifies preexisting life patterns.

(SEE ALSO: Advertising of Unhealthy Products; Information System; Information Technology; Patient Education Media; Self-Help Groups; Social Health)

— MIKE CHIASSON

Biologists often use two terms to describe alternative approaches for conducting experiments. "In vitro" (Latin for "in glass") refers to experiments typically carried out in test tubes with purified biochemicals. "In vivo" ("in life") experiments are performed directly on living organisms. In recent years, the indispensable use of computers and the Internet for genetic and molecular biology research has introduced a new term into the language: "in silico" ("in silicon"), referring to the silicon used to manufacture computer chips. In silico genetics experiments are those that are performed with a computer, often involving analysis of DNA or protein sequences over the Internet.

Geneticists and molecular biologists use the Internet much the same way most people do, communicating data and results through e-mail and discussion groups and sharing information on Web sites, for instance. They also make wide use of powerful Internet-based databases and analytical tools. Researchers are determining the DNA sequences of entire genomes at an ever accelerating pace, and are devising methods for cataloging entire sets of proteins (termed "proteomes") expressed in organisms. The databases to store all this information are growing at an equal pace, and the computer tools to sort through all the data are becoming increasingly sophisticated.

One of the most important Web sites for biological computer analysis (sometimes called bioinformatics) is that of the National Center for Biotechnology Information (NCBI), a part of the National Library of Medicine, which, in turn, is part of the National Institutes of Health. The NCBI Web site hosts DNA and protein sequence databases, protein three-dimensional structure databases, scientific literature databases, and search engines for retrieving files of interest. All of these resources are freely accessible to anyone on the Internet.

Of all the powerful analytical tools available at NCBI, probably the most important and heavily used is a set of computer programs called BLAST, for Basic Local Alignment Search Tool. BLAST can rapidly search many sequence databases to see whether any DNA or protein sequence (a "query sequence," supplied by the user) is similar to other sequences. Since sequence similarity usually suggests that two proteins or DNA molecules are homologous (i.e., that they are evolutionarily related and therefore may have—or encode proteins—with similar functions), discovering a blast match between an unknown protein or nucleic acid sequence and a well-characterized sequence provides an immediate clue about the function of the unknown sequence. An important scientific discovery that, in the past, may have taken many years of in vitro and in vivo analysis to arrive at is now made in a few seconds, with this simple in silico experiment.

Bibliography

Internet Resources

Basic Local Alignment Search Tool. National Center for Biotechnology Information. http://www.ncbi.nlm.nih.gov/BLAST/.

Baxevanis, Andreas D. "The Molecular Biology Database Collection: 2002 Update." Nucleic Acids Research. Oxford University Press. http://www3.oup.co.uk/nar/database/.

ExPASy Molecular Biology Server. Swiss Institute of Bioinformatics. http://ca.expasy.org/.

Virtual Library of Genetics. U.S. Department of Energy. http://www.ornl.gov/TechResources/Human_Genome/genetics.html.

Wellcome Trust Sanger Institute. http://www.sanger.ac.uk/.

WWW Virtual Library: Model Organisms. George Manning. http://ceolas.org/VL/mo/.

—Paul J. Muhlrad

For more information on Internet, visit Britannica.com.

By the late 20th century the internet had become the principal global means of information exchange for individuals as well as multinational corporations. Its origins lay in the internal linking of computers in the US Defense Department in the 1960s and research relating to the control of missiles and bombers. These so-called intranets evolved into the internet (a contraction of ‘internetwork’), a term first used in the 1970s but increasingly widely used from the later 1980s and early 1990s. The networking of computers was first publicly seen at the 1972 International Computer Communication Conference (ICCC), the same year in which early applications of electronic mail were being explored. Other developments followed as efforts intensified to build communications between different groups of researchers or military constituencies. The introduction of the internet as it is recognized today was facilitated by cooperation between US federal agencies and other international organizations. The World Wide Web, a term that came into current usage in the 1990s, was a means of accessing information—text, graphics, sound, visual, moving image, and virtual reality. It became a vehicle for a whole range of electronic (or ‘e-’) services such as shopping, banking, travel, and insurance as well as an increasingly prominent means of personal and business communication, e-mail. Its popularity was closely interlinked with the widespread use of Personal Computers (PCs) and the international proliferation of internet cafés, providing individuals with almost limitless possibilities for communication. The design of websites—increasingly important to corporations, public institutions, and organizations as a means of giving them a competitive edge—has become a highly profitable aspect for graphic, communication, and multimedia design consultancies, although it has become increasingly common for individuals and families to design their own.

The Internet has become an important medium for photographers because it enables images to be transmitted, displayed, and downloaded to computers extremely rapidly worldwide. Photography on the Internet is possible because scanners (and later digital cameras) have been developed to capture images electronically. The first drum scanner was built for the SEAC computer at the US National Bureau of Standards in 1957 by a team led by Russell A. Kirsch (whose other major contribution was to codify the square ‘pixel’ as the basic unit of a digital picture).

The Internet itself grew out of the ARPANET, a network developed under the direction of Dr J. C. R. Licklider of the Advanced Research Projects Agency to link major research centres in the USA. The key to the network's flexibility was its decentralized design, involving routers sending packets of information via all possible connections. The ARPANET was commissioned by the US Department of Defense in 1969 and continued to grow throughout the 1970s. By the 1980s independent service providers and bulletin boards were continuing to multiply, and the Internet Activities Board was founded in 1983. The ARPANET ceased to exist in 1990, by which time it had been superseded by its progeny.

The Internet developed as a visual medium when the first graphical browsers became available. In 1989 Tim Berners-Lee at the Centre Européenne de Recherche Nucléaire (CERN) proposed a web browser that would display webpages consistently across all computers. With the addition of standardized display formats, the World Wide Web (WWW) came into its own from the mid-1990s. Photographs displayed on the Internet are generally shown as JPEG files (invented by the Joint Photographic Experts Group in 1990), GIF files (Graphics Interchange Format, developed by Bob Berry of Compuserve in 1987), and the non-proprietary PNG format (portable network graphics, a free alternative to GIF, developed by Thomas Boutell from 1995). The JPEG is generally used for photographs whilst the GIF is more suitable for geometric shapes and line art. All these formats involve compression, which means that the image's file size is reduced by simplifying its range of colours. Heavy compression results in obvious image degradation, so there is a trade-off between file size and image quality.

The Internet may be used by photographers in several ways. The most obvious is the online gallery, which can showcase one photographer's work or act as a larger repository (e.g. for agencies or picture archives). It presents photographs in a similar way to its physical counterpart, but with the added flexibility of dynamic links and search options to assist viewers. Its layout and style influence its attractiveness to new visitors. The gallery may also be used to sell photographs directly, acting as an online shop. This is useful to freelance photographers wanting to distribute their work, which may be downloaded as secure files or physically mailed to the buyer as prints. Here, the photograph on the website is only a representation of the print, not a substitute for it. The popularity of web-based diaries and writings (weblogs or blogs) has led to collections of images posted as photo journals. Although these are generally by amateurs, the Internet has become a major outlet for online photojournalism. The net speeds delivery of news and photographs, allowing freelancers and small groups to compete with large news agencies. This has broadened the spread of news photography, although some traditional photojournalists fear their skills are being displaced by low-resolution Internet images.

The web's interactive forums also allow the widespread discussion of photographic issues, and interactive reviews of new equipment. This benefits both traditional and digital photographers who want to raise questions or develop their skills. These forums also bring new techniques and concerns to light in a worldwide community of photographers. Other sites teach online photographic courses. The Internet also enables large and rarely seen photographic archives—and document collections like the Talbot Correspondence—to be placed online, often as part of major academic projects. For instance, the 17 million photographs of the Bettmann archive, spanning the 20th century, are to be relocated to a mine north-east of Pittsburgh for preservation underground. Their digitized contents will be made available online with other Corbis holdings. However, the physical inaccessibility of the archive concerns some historians, even though the storage conditions will preserve its actual substance. Another problem relating to this and other large collections is the time it takes to digitize material.

Copyright is a major issue with Internet photography. As with music files, images can be downloaded from websites and used without their owners' permission. The nature of digital data makes copying extremely easy, and although various technologies, including encryption and digital watermarking, are designed to prevent illegal use of images, most can be circumvented. Additionally, older photographs can be scanned and placed in the digital domain. The resulting problems extend from straightforward breach of copyright to more complex issues such as illegal alteration of images. By 2000 this had become both easy and widespread. In 2004 a widely published composite picture ‘showed’ the US presidential candidate John Kerry with Jane Fonda at an anti-Vietnam War protest. It was not only used without the original photographers' permission, but modified for political purposes and posted on websites under the false imprint of Associated Press: a veritable catalogue of infringements. Another notorious 21st-century problem is the creation of pornography at offshore locations and its distribution via the Internet. However, notwithstanding these and other concerns, it seems certain that the Internet will continue to expand rapidly, and probable that, overall, its utility to photographers will continue to outweigh its dangers.

— Nick Lambert

Bibliography

• Mitchell, W. J., The Reconfigured Eye: Visual Truth in the Post-Photographic Era (1992).
• Hoffman, B. (ed.), Exploiting Images and Image Collections in the New Media: Goldmine or Legal Minefield? (1999).
• Andrews, P., The Photographer's Website Manual: The Indispensable Guide to Building and Running a Website (2003)

Arguably the most important communications tool ever created, the Internet connects millions of people to online resources each day. Grown from seeds planted during the Cold War, the roots of the Internet were formed to develop a reliable, national system for communications. Although early pioneers disagree over whether the computer-based communications network was built to withstand nuclear attack, the uneasy tension between the United States and the Soviet Union during the Cold War certainly increased the resolve of the United States to fund and develop relevant scientific and defense-related projects aimed at national security.

Home to many of the preeminent scientists of the time, the Massachusetts Institute of Technology (MIT) served as the birthplace of the Internet. It was there, in Cambridge, Massachusetts, that President Harry Truman's administration formed MIT's Lincoln Laboratories to begin work on the Semi-Automatic Ground Environment. SAGE's primary goal was to develop an air defense system that involved a network of interconnected computers across the United States. The push for advanced technology received an even larger boost in August 1957, when the Soviet Union test fired its first intercontinental ballistic missile and subsequently launched its Sputnik orbiter in October of that same year. Shortly thereafter, President Dwight D. Eisenhower convened a meeting of his Presidential Science Advisory Committee. From that meeting and subsequent congressional testimony on the progress of U.S. defense and missile programs, it became clear that the "science gap" between the two superpowers had widened. Eisenhower sought funding for the Advanced Research Projects Agency (ARPA) late in 1957 and obtained it the following year.

In the early 1960s, the Lincoln Laboratory researchers Lawrence Roberts and Leonard Kleinrock worked on developing a method of digitizing and transmitting information between two computers using a communications method called packet switching. Similar work on systems that used store-and-forward switching was also underway in the late 1950s under the direction of Paul Baran and Donald Davies at the National Physical Laboratory in England. At the heart of both research projects was the development of a communications system in which information would be distributed among all nodes on a network, so that if one or more nodes failed, the entire network would not be disabled. This type of network, in which messages were passed from node to node, with no single node responsible for the end-to-end traffic, was called hot-potato routing.

ARPA's first director, J. C. R. Licklider, moved from Lincoln Laboratory to a small Cambridge, Massachusetts–based consulting firm, Bolt, Beranek, and Newman (BBN), where researchers continued to explore the use of computers as tools of communication. While there, Licklider and his colleagues developed the necessary hardware to connect computers to telephone lines and also researched the collection of data from a wide array of other sources including antennae, submarines, and other real-time sensors. Most of BBN's projects were ARPA supported and sought to achieve ARPA's ultimate goal of helping close the science gap by creating a nationwide network of interconnected computers.

In the summer of 1968, ARPA issued a request for proposals to more than 130 different research centers with the goal of creating a digital network of computers conforming to ARPA's technical specifications. Roberts developed the criteria and served as the chief architect of the network's overall design, which included the deployment of "packet switching technology, using half-second response time, with measurement capability, and continuous operation"—that is, an Internet. Frank Heart and the team of scientists at BBN were awarded the contract in December 1968.Outfitted with specialized minicomputers and interface hardware, BBN set out to connect their "packet switches" or Interface Message Processors

(IMPs), at each ARPA-determined remote location (node), which would then communicate with the host computer at that location. Robert Kahn and Vincent Cerf, with Jon Postel and Charles Kline, developed the software to connect host computers to the IMPs, a host-to-host protocol on how packets would be routed. While America was absorbed in NASA's race to land on the moon in the summer of 1969, BBN air shipped its first IMP computer across the country—no small feat for the time. It arrived safely and was working at the first node, the University of California at Los Angeles, in August 1969.

This phase of the ARPA-BBN project was completed in nine months. Meanwhile, work continued on equipping the second node, the Stanford Research Institute (SRI) in Palo Alto—some four hundred miles away—to the interface message processor. On 1 October 1969 the Stanford node came online and the first message, "LO," was passed that day. BBN continued to progress, installing nodes three and four at the University of California at Santa Barbara (1 November 1969) and the University of Utah (1 December 1969).Only in March of the following year did BBN connect its Cambridge offices to the newly created ARPAnet.

The ARPAnet continued to evolve through the early 1970s with the addition of more diverse data networks such as the University of Hawaii's ALOHAnet packet radio network and the European-based packet satellite network. During this period, the first terminal interface processor (TIP) was introduced to the network, thereby allowing computer terminals to call directly into the ARPAnet using standard telephone lines. In 1972, the first electronic messaging program (e-mail) that supported incoming and outgoing messages was developed. In that same year, a file transfer protocol specification (FTP) to allow for the transmission of data files across the network was designed and tested. With these additions, ARPAnet truly began to fulfill its mission as an open-architecture network, accommodating a variety of different environments and allowing the free sharing of resources.

As the uses of the network grew, more efficient methods for carrying data were needed, forcing an evolution of transmission protocols—the underlying control layer in which the messages flowed—and addressing schemes. After many refinements, TCP/IP (transmission control protocol/Internet protocol) became the de facto standard for communicating on the network. A naming scheme also became necessary and the Domain Name System (DNS) was developed by Paul Mockapetris of the University of Southern California. DNS allowed for the assignment of names to networks and nodes, supplanting the use of numeric addresses. In 1973, Ethernet technology was developed, allowing for the rapid addition of nodes and workstations to the network. With the birth of the personal computer and local area networks (LANs) in the early 1980s, the network grew at a staggering pace.

The federal government funded the network and its infrastructure through 1995.The work of the National Science Foundation (NSF) was instrumental for under-standing the future evolution of the Internet as a true "information superhighway." However, federal funding of the Internet was terminated as a result of the NSF's privatization initiative to encourage commercial network traffic. Control of the large backbones of the network—the set of paths with which local or regional networks connected for long-haul connectivity—was redistributed to private regional network service providers.

The Internet serves as a vital network of communication in the form of e-mail, news groups, and chat. It also provides unparalleled resource sharing and resource discovery through the World Wide Web. At the end of 2001, the Internet continued its phenomenal annual rate of growth of 100 percent. At its start in 1981, the Internet connected just over two hundred researchers and scientists. By the end of 2002, it is estimated that the Internet had the capacity to reach more than six billion people worldwide.

Bibliography

Abbate, Janet. Inventing the Internet. Cambridge, Mass.: MIT Press, 1999.

Hauben, Michael, and Ronda Hauben. Netizens: On the History and Impact of Usenet and the Internet. Los Alamitos, Calif.: IEEE Computer Society Press, 1997.

Quarterman, John S., and Smoot Carl-Mitchell. The Internet Connection: System Connectivity and Configuration. Reading, Mass.: Addison-Wesley, 1994.

Segaller, Stephen. Nerds 2.0.1: A Brief History of the Internet. New York: TV Books, 1998.

The Internet is the world's largest computer network. It links computer terminals together via wires or telephone lines in a web of networks and shared software. With the proper equipment, an individual can access vast amounts of information and search databases on various computers connected to the Internet, or communicate with someone located anywhere in the world as long as he or she has the proper equipment.

Originally created in the late 1960s by the U.S. Department of Defense Advanced Research Projects Agency to share information with other researchers, the Internet mushroomed when scientists and academics using the network discovered its great value. Despite its origin, however, the Internet is not owned or funded by the U.S. government or any other organization or institution. A group of volunteers, the Internet Society, addresses such issues as daily operations and technical standards.

The Internet is a vast worldwide conglomeration of linked computer networks. Its roots lie in the mid-twentieth century, with a number of projects by the United States government and the private sector, most notable of which was the computer network created by the Advanced Research Projects Agency (ARPA) of the Department of Defense (DOD) in 1969. Until the early 1990s, the Internet remained largely the province of specialists, including defense personnel and scientists. The creation of browsers, or software that provided a convenient graphical interface between user and machine, revolutionized the medium, and spawned rapid economic growth throughout the 1990s. In addition to the World Wide Web and e-mail, the parts of the Internet most familiar to casual users, the Internet contains a frontier that offers both great promise and great challenges to law and security.

Birth of the Internet

The basis of the Internet is the network, a group of computers linked by communication lines. The distant ancestors of today's networks were highly specialized systems used either by DOD, or by private companies (for example, airlines, which tracked reservations on the SABRE system) during the late 1950s and early 1960s. The development of semiconductor technology in the 1960s enabled the growth of computer activity in general, and networking in particular. Universities and research centers participated in timesharing, whereby multiple users accessed the same system.

ARPANET, which connected time-sharing facilities at research centers, is generally regarded as the first true computer network. It provided a testing-ground for technologies that are still used today: simple mail transfer protocol (SMTP), the system that makes e-mail possible, and file transfer protocol (FTP), for transmitting large messages. To maximize effectiveness, ARPANET broke messages into small pieces, or packets, that could easily be transmitted and reassembled. The technique, known as packet switching, enhanced communication between computers.

The 1970s: TCP/IP. During the 1970s, ARPA (now known as the Defense Advanced Research Projects Agency, or DARPA) continued its efforts to connect its users, but it eventually ran into a dead-end posed by the primitive systems of networking used at the time. Faced with this roadblock, DARPA turned to two computer scientists, Vinton Cerf and Robert Kahn, who developed a design that revolutionized networks.

This was the transmission control protocol (TCP), which, coupled with the related Internet Protocol (IP), provided a mechanism for addressing messages and routing them to their destinations using an open architecture that connected standardized networks. In 1980, DOD adopted TCP/IP as its standard, and required all participants to adopt the protocol as of January 1, 1983. Some observers regard this event as the true birth of the Internet.

The 1980s: civilian agencies get involved. The 1980s saw use of computer networks expand to include civilian agencies. Among these was the National Science Foundation (NSF), which worked with five supercomputing centers spread across the country to create NSFNET, a "backbone" system intended to connect the entire nation. NSF succeeded in linking small local and regional networks to NSFNET. Other civilian participants in computer networks, which began to increasingly overlap with one another, included the Department of Energy and the National Aeronautics and Space Administration (NASA), as well as a number of private companies.

Also during this period, several independent consortiums took on themselves the task of organizing and policing the rapidly growing Internet. Among these were the Internet Engineering Task Force and the Internet Society, both of which are concerned with Internet standards, as well as the Internet Corporation for Assigned Names and Numbers (ICANN). The latter controls policy with regard to the assignment of domain names, including top-level domains such as .com for commercial enterprises, .gov for government offices, .edu for schools, and so on.

The Internet Explosion

The mid-1980s saw the birth of the first commercial computer networks, including Prodigy, Compuserve, and Quantum Computer Services. The first two would eventually recede in significance as larger companies took over the Internet, but the third—founded in 1985 and renamed America Online (AOL) in 1989—would eventually merge with publishing and entertainment conglomerate Time Warner to control a wide span of media. All of that lay far in the future, however, during the mid-1980s, as the few commercial participants developed their first subscriber bases and linked up to NSFNET through the Commercial Internet Exchange (CIX).

A number of technological innovations in the 1980s and early 1990s portended the explosive growth of the Internet that would take place in the next decade. Among these was the development of the personal computer or PC, as well as local area networks (LANs), which linked computers within a single business or location. NSFNET, working with the Corporation for National Research Initiatives, sponsored the first commercial use of e-mail on the Internet. Then, in 1993, new legislation at the federal level permitted the full opening of the NSFNET to commercial users.

The result was much like the opening of lands in the western United States to homesteaders, only the "land" in this case existed in virtual or cyberspace, and instead of wagons, the new settlers used browsers. The first important browser was Mosaic, developed at the University of Illinois using standards created at the European Organization for Nuclear Research (CERN) by Tim Berners-Lee. Thus was born the World Wide Web, which uses hypertext transfer protocol, or HTTP. In this environment, Mosaic—known as Netscape Navigator after the formation of the Netscape Communications Corporation in 1994—and Microsoft's competing Internet Explorer would prove the most useful navigating tools.

Users of the Internet today can still travel to regions beyond the World Wide Web, where they can see what the Internet was like prior to 1993. The most significant surviving portion of this older section is Usenet, a worldwide bulletin board system containing some 14,000 forums or newsgroups. In addition to the Web and Usenet, the Internet includes e-mail (electronic mail), FTP sites (used for transferring pictures and other large files), instant messaging, and other components. At the edges of the Internet are proprietary services such as those accessible only to AOL users, as well as other pay sites. Additionally, company and government intranets (private networks accessible only through a password) lie beyond the periphery of the Internet, though a browser may be used to access both.

By 1988, the size of the Internet was doubling every year, and the advent of browsers made possible an enormous consumer influx. The mid-to late 1990s saw the formation of thousands of Internet service providers (ISPs), through which users gained access to the Internet in exchange for a monthly fee. As competition increased, fees decreased, forcing consolidation of providers. By the beginning of the twenty-first century, major companies such as AOL, AT&T, and Earthlink, along with a few second-tier ISPs, controlled most of the market.

The explosive growth of the Internet itself, coupled with the expanded opportunities for commerce it provided, fueled one of the greatest periods of economic growth in U.S. history, from 1996 to 2000. The economic downturn that began in April, 2000, and continued throughout the early 2000s, however, served as an indicator that the Internet—while it had certainly transformed communications—would not solve all problems.

There were several problems associated with the Internet itself, and simplest among these were the technological challenges involved in moving ever larger amounts of data. By the beginning of the twenty-first century, it became possible to access video and complex graphics using powerful data streams, and computer scientists envisioned technology that would make possible the use of high-resolution video or multiple streams on networks capable of processing 100 gigabits of data a second. To expand the number of available addresses, hitherto limited by the 32-bit IP address standard, the Internet Engineering Task Force in 1998 approved a new 128-bit standard. This made possible so many addresses that every electronic device in the world could have its own unique location in an ever-expanding Internet.

Less simple were some of the challenges associated with human activities. There were cybercrimes, such as hacking or the dissemination of viruses, either of which could be used simply as a form of information-age vandalism, or for extortion. Hacking of financial service sites also offered the opportunity to commit robbery without picking locks, and for this reason many companies adopted secure, encrypted sites. (The latter were designated by the prefix https://, in contrast to the ordinary http://.)

Just as the Internet could be used for education, commerce, and a host of other purposes, it also provided a forum for activities that tested the limits of free speech; extremist political parties and hate groups could operate a Web site. On the other hand, use of the Web to distribute drugs, weapons, or child pornography carried stiff penalties. At the same time, government attempts to restrict or control aspects of the Internet raised concerns over the abrogation of First Amendment rights. The Internet itself was worldwide, beyond the reach of even the U.S. Constitution or any law, and although China's totalitarian regime attempted to restrict citizens' access to it, the network continued to work its way deeper and deeper into the fabric of modern life.

Further Reading

Books

Gillies, James, and R. Cailliau. How the Web Was Born: The Story of the World Wide Web. New York: Oxford University Press, 2000.

Hafner, Katie, and Matthew Lyon. Where Wizards Stay Up Late: The Origins of the Internet. New York: Simon & Schuster, 1996.

Young, Gray, ed. The Internet. New York: H. W. Wilson, 1998.

Electronic

Defense Advanced Research Projects Agency. <http://www.darpa.mil/> (April 14, 2003).

Internet Society. <http://www.isoc.org/> (April 14, 2003).

Webopedia: Online Dictionary for Computer and Internet Terms. <http://www.webopedia.com/> (April 14, 2003).

A worldwide telecommunications network of business, government, and personal computers.

The Internet is a network of computers linking the United States with the rest of the world. Originally developed as a way for U.S. research scientists to communicate with each other, by the mid-1990s the Internet had become a popular form of telecommunication for personal computer users. The dramatic growth in the number of persons using the network heralded the most important change in telecommunications since the introduction of television in the late 1940s. However, the sudden popularity of a new, unregulated communications technology raised many issues for U.S. law.

The Internet, popularly called the Net, was created in 1969 for the U.S. Department of Defense. Funding from the Advanced Research Projects Agency (ARPA) allowed researchers to experiment with methods for computers to communicate with each other. Their creation, the Advanced Research Projects Agency Network (ARPANET), originally linked only four separate computer sites at U.S. universities and research institutes, where it was used primarily by scientists.

In the early 1970s, other countries began to join ARPANET, and within a decade it was widely accessible to researchers, administrators, and students throughout the world. The National Science Foundation (NSF) assumed responsibility for linking these users of ARPANET, which was dismantled in 1990. The NSF Network (NSFNET) now serves as the technical backbone for all Internet communications in the United States.

The Internet grew at a fast pace in the 1990s as the general population discovered the power of the new medium. A significant portion of the Net's content is written text, in the form of both electronic mail (E-mail) and articles posted in an electronic discussion forum known as the Usenet news groups. In the mid-1990s the appearance of the World Wide Web made the Internet even more popular. The Web is a multimedia interface that allows for the transmission of text, pictures, audio, and video together, known as Web pages, which commonly resemble pages in a magazine. Together these various elements have made the Internet a medium for communication and for the retrieval of information on virtually any topic.

The sudden growth of the Internet caught the legal system unprepared. Before 1996 there was little federal legislation on this form of telecommunication. In 1986 Congress passed the Electronic Communications Privacy Act (ECPA) (18 U.S.C.A. § 2701 et seq. [1996]), which made it illegal to read private E-mail. The ECPA extended most of the protection already granted to conventional mail to electronic mail. Just as the post office may not read private letters, neither can the providers of private bulletin boards, on-line services, or Internet access. However, law enforcement agencies can subpoena E-mail in a criminal investigation. The ECPA also permits employers to read their workers' E-mail. This provision was intended to protect companies against industrial spying but has generated lawsuits from employees who objected to the invasion of their privacy. Federal courts, however, have allowed employers to secretly monitor an employee's E-mail on a company-owned computer system, concluding that employees have no reasonable expectation of privacy when they use company E-mail.

Criminal activity on the Internet generally falls into the category of computer crime. It includes so-called hacking, or sneaking into computer systems, stealing account passwords and credit-card numbers, and illegally copying intellectual property. Because personal computers can easily copy information — including everything from software to photographs and books — and the information can be sent anywhere in the world quickly, it has become much more difficult for copyright owners to protect their work.

Public and legislative attention has focused on Internet content, specifically sexually explicit material. The distribution of pornography became a major concern in the 1990s, as private individuals and businesses found an unregulated means of giving away or selling pornographic images. As hard-core and child pornography proliferated, Congress sought to impose restrictions on obscene and indecent content on the Internet.

In 1996 Congress passed the Communications Decency Act (CDA) as part of the Telecommunications Competition and Deregulation Act of 1996 (47 U.S.C.A. § 223(a)(h)). The CDA forbade the dissemination of obscene or indecent material to children through computer networks or other telecommunications media. The act included penalties for knowing violations of up to five years imprisonment and fines of up to $250,000. First Amendment advocates and on-line services immediately brought suit to challenge the act as an unconstitutional restriction on free speech. A special three-judge federal panel in Pennsylvania agreed with these groups, concluding that the law was overly broad because, in attempting to protect children, it would also limit the speech of adults (American Civil Liberties Union v. Reno, 929 F.Supp. 824 [1996]). On June 26, 1997, the Supreme Court affirmed, finding the challenged provisions overbroad (1997 WL 348012).

Another area of legal concern is the issue of libel. In tort law libel and slander occur when the communication of false information about a person injures the person's good name or reputation. Where the traditional media are concerned, it is well settled that libel suits provide both a means of redress for injury and a punitive corrective against sloppiness and malice. Regarding communication on the Internet, however, there is little case law, especially on the key issue of liability.

In suits against newspapers, courts traditionally held publishers liable, along with their reporters, because publishers were presumed to have reviewed the libelous material prior to publication. Because of this legal standard, publishers and editors are generally careful to review anything they publish. However, the Internet is not a body of material carefully reviewed by a publisher, but an unrestricted flood of information. If a libelous or defamatory statement is posted on the Internet, which is essentially owned by no one, the law is uncertain about whether anyone other than the author can be held liable.

Some courts have held that on-line service providers, companies that connect their subscribers to the Internet, should be held liable if they allow their users to post libelous statements on their sites. An on-line provider is thus viewed like a traditional publisher.

Other courts have rejected the publisher analogy and have instead compared Internet service providers to bookstores. Like bookstores, providers are distributors of information and cannot reasonably be expected to review everything they sell. U.S. libel law gives greater protection to bookstores because of this theory (Smith v. California, 361 U.S. 147, 80 S. Ct. 215, 4 L. Ed. 2d 205 [1959]), and some courts have applied it to on-line service providers.

The continued growth of the Internet (twenty-four million subscribers in 1995) has placed enormous burdens on telephone networks. Telephone systems were not designed to handle thousands of Internet connections that may last several hours at a time. Telephone companies, concerned about their capacity to handle the volume of both voice and electronic communication, have proposed changing rate structures and raising rates for Internet users that reflect the higher demands placed on the telephone systems.

See: telecommunications.

Internetworking

Quotes:

"Information on the Internet is subject to the same rules and regulations as conversation at a bar." - George Lundberg

"The difference between e-mail and regular mail is that computers handle e-mail, and computers never decide to come to work one day and shoot all the other computers." - Jamais Cascio

"In Cyberspace, the 1st Amendment is a local ordinance." - John Perry Barlow

"The ides of surfing the net -- I don't know who called it that -- it's more like slogging through the net." - Al Di Guido

For other uses, see Internet (disambiguation).

Visualization of the various routes through a portion of the Internet

The Internet is a global system of interconnected computer networks that use the standardized Internet Protocol Suite (TCP/IP). It is a network of networks that consists of millions of private and public, academic, business, and government networks of local to global scope that are linked by copper wires, fiber-optic cables, wireless connections, and other technologies.

The Internet carries a vast array of information resources and services, most notably, the inter-linked hypertext documents of the World Wide Web (WWW) and the infrastructure to support electronic mail, in addition to popular services such as online chat, file transfer and file sharing, online gaming, and Voice over Internet Protocol (VoIP) person-to-person communication via voice and video.

The origins of the Internet reach back to the 1960s when the United States funded research projects of its military agencies to build robust, fault-tolerant and distributed computer networks. This research and a period of civilian funding of a new U.S. backbone by the National Science Foundation spawned worldwide participation in the development of new networking technologies and led to the commercialization of an international network in the mid 1990s, and resulted in the following popularization of countless applications in virtually every aspect of modern human life. By 2009, an estimated quarter of Earth's population uses the services of the Internet (see Growth).

Contents 1 Terminology 2 History 2.1 Creation 2.2 Growth 3 Technical foundation 4 Today's Internet 4.1 Internet structure 4.2 ICANN 4.3 Language 4.4 Internet and the workplace 4.5 The Internet viewed on mobile devices 5 Common uses 5.1 E-mail 5.2 The World Wide Web 5.3 Remote access 5.4 Collaboration 5.5 File sharing 5.6 Streaming media 5.7 Internet Telephony (VoIP) 6 Internet by region 7 Internet access 8 Social impact 8.1 Digital Natives 8.2 Political organization and censorship 8.3 Leisure activities 9 Market 10 See also 11 Notes 12 References 13 External links

Terminology

See also: Internet capitalization conventions

Look up Internet or internet in Wiktionary, the free dictionary.

The terms Internet and World Wide Web are often used in everyday speech without much distinction. However, the Internet and the World Wide Web are not one and the same. The Internet is a global data communications system. It is a hardware and software infrastructure that provides connectivity between computers. In contrast, the Web is one of the services communicated via the Internet. It is a collection of interconnected documents and other resources, linked by hyperlinks and URLs.^[1]

The term the Internet, when referring to the Internet, has traditionally been treated as a proper noun and written with an initial capital letter. There is a trend to regard it as a generic term or common noun and thus write it as "the internet", without the capital.

History

Main article: History of the Internet

Creation

The USSR's launch of Sputnik spurred the United States to create the Advanced Research Projects Agency, known as ARPA, in February 1958 to regain a technological lead.^[2][3] ARPA created the Information Processing Technology Office (IPTO) to further the research of the Semi Automatic Ground Environment (SAGE) program, which had networked country-wide radar systems together for the first time. J. C. R. Licklider was selected to head the IPTO.

Licklider moved from the Psycho-Acoustic Laboratory at Harvard University to MIT in 1950, after becoming interested in information technology. At MIT, he served on a committee that established Lincoln Laboratory and worked on the SAGE project. In 1957 he became a Vice President at BBN, where he bought the first production PDP-1 computer and conducted the first public demonstration of time-sharing.

At the IPTO, Licklider got Lawrence Roberts to start a project to make a network, and Roberts based the technology on the work of Paul Baran,^[4] who had written an exhaustive study for the U.S. Air Force that recommended packet switching (as opposed to circuit switching) to make a network highly robust and survivable. After much work, the first two nodes of what would become the ARPANET were interconnected between UCLA and SRI International (SRI) in Menlo Park, California, on October 29, 1969. The ARPANET was one of the "eve" networks of today's Internet.

Following on from the demonstration that packet switching worked on the ARPANET, the British Post Office, Telenet, DATAPAC and TRANSPAC collaborated to create the first international packet-switched network service. In the UK, this was referred to as the International Packet Switched Service (IPSS), in 1978. The collection of X.25-based networks grew from Europe and the US to cover Canada, Hong Kong and Australia by 1981. The X.25 packet switching standard was developed in the CCITT (now called ITU-T) around 1976.

Birth of the Internet plaque at Stanford University

X.25 was independent of the TCP/IP protocols that arose from the experimental work of DARPA on the ARPANET, Packet Radio Net and Packet Satellite Net during the same time period. Vinton Cerf and Robert Kahn developed the first description of the TCP protocols during 1973 and published a paper on the subject in May 1974. Use of the term "Internet" to describe a single global TCP/IP network originated in December 1974 with the publication of RFC 675, the first full specification of TCP that was written by Vinton Cerf, Yogen Dalal and Carl Sunshine, then at Stanford University. During the next nine years, work proceeded to refine the protocols and to implement them on a wide range of operating systems.

The first TCP/IP-based wide-area network was operational by January 1, 1983 when all hosts on the ARPANET were switched over from the older NCP protocols. In 1985, the United States' National Science Foundation (NSF) commissioned the construction of the NSFNET, a university 56 kilobit/second network backbone using computers called "fuzzballs" by their inventor, David L. Mills. The following year, NSF sponsored the conversion to a higher-speed 1.5 megabit/second network. A key decision to use the DARPA TCP/IP protocols was made by Dennis Jennings, then in charge of the Supercomputer program at NSF.

The opening of the network to commercial interests began in 1988. The US Federal Networking Council approved the interconnection of the NSFNET to the commercial MCI Mail system in that year and the link was made in the summer of 1989. Other commercial electronic e-mail services were soon connected, including OnTyme, Telemail and Compuserve. In that same year, three commercial Internet service providers (ISPs) were created: UUNET, PSINet and CERFNET. Important, separate networks that offered gateways into, then later merged with, the Internet include Usenet and BITNET. Various other commercial and educational networks, such as Telenet, Tymnet, Compuserve and JANET were interconnected with the growing Internet. Telenet (later called Sprintnet) was a large privately funded national computer network with free dial-up access in cities throughout the U.S. that had been in operation since the 1970s. This network was eventually interconnected with the others in the 1980s as the TCP/IP protocol became increasingly popular. The ability of TCP/IP to work over virtually any pre-existing communication networks allowed for a great ease of growth, although the rapid growth of the Internet was due primarily to the availability of an array of standardized commercial routers from many companies, the availability of commercial Ethernet equipment for local-area networking, and the widespread implementation and rigorous standardization of TCP/IP on UNIX and virtually every other common operating system.

Growth

Graph of Internet users per 100 inhabitants between 1997 and 2007 by International Telecommunication Union

Although the basic applications and guidelines that make the Internet possible had existed for almost two decades, the network did not gain a public face until the 1990s. On 6 August 1991, CERN, a pan European organisation for particle research, publicized the new World Wide Web project. The Web was invented by English scientist Tim Berners-Lee in 1989.

An early popular web browser was ViolaWWW, patterned after HyperCard and built using the X Window System. It was eventually replaced in popularity by the Mosaic web browser. In 1993, the National Center for Supercomputing Applications at the University of Illinois released version 1.0 of Mosaic, and by late 1994 there was growing public interest in the previously academic, technical Internet. By 1996 usage of the word Internet had become commonplace, and consequently, so had its use as a synecdoche in reference to the World Wide Web.

Meanwhile, over the course of the decade, the Internet successfully accommodated the majority of previously existing public computer networks (although some networks, such as FidoNet, have remained separate). During the 1990s, it was estimated that the Internet grew by 100 percent per year, with a brief period of explosive growth in 1996 and 1997.^[5] This growth is often attributed to the lack of central administration, which allows organic growth of the network, as well as the non-proprietary open nature of the Internet protocols, which encourages vendor interoperability and prevents any one company from exerting too much control over the network. ^[6]

Using various statistics, Advanced Micro Devices estimated the population of Internet users to be 1.5 billion as of January 2009.^[7]

Technical foundation

Further information: Internet Protocol Suite

The complex communications infrastructure of the Internet consists of its hardware components and a system of software layers that control various aspects of the architecture. While the hardware can often be used to support other software systems, it is the design and the rigorous standardization process of the software architecture that characterizes the Internet and provides the foundation for its scalability and success.

The responsibility for the architectural design of the Internet software systems has been delegated to the Internet Engineering Task Force (IETF).^[8] The IETF conducts standard-setting work groups, open to any individual, about the various aspects of Internet architecture. Resulting discussions and final standards are published in a series of publications each of which is called a Request for Comment (RFC), freely available on the IETF web site. The principal methods of networking that enable the Internet are contained in specially designated RFCs that constitute the Internet Standards.

These standards describe a framework known as the Internet Protocol Suite. This is a model architecture that divides methods into a layered system of protocols (RFC 1122, RFC 1123). The layers correspond to the environment or scope in which their services operate. At the top is the Application Layer, the space for the application-specific networking methods used in software applications, e.g., a web browser program, and just below it is the Transport Layer which connects applications on different hosts via the network (e.g., client-server model) with appropriate data exchange methods. Underlying these layers are the actual networking technologies, consisting of two layers. The Internet Layer enables computers to identify and locate each other via Internet Protocol (IP) addresses, and allows them to connect to one-another via intermediate (transit) networks. Lastly, at the bottom of the architecture, is a software layer that provides connectivity between hosts on the same local network link (therefor called Link Layer), such as a local area network (LAN) or a dial-up connection. The model, also known as TCP/IP, is designed to be independent of the underlying hardware which the model therefore does not concern itself with in any detail. Other models have been developed, such as the Open Systems Interconnection (OSI) model, but they are not compatible in the details of description, nor implementation, but many similarities exist and the TCP/IP protocols are usually included in the discussion of OSI networking.

The most prominent component of the Internet model is the Internet Protocol (IP) which provides addressing systems (IP addresses) for computers on the Internet. IP enables internetworking and essentially establishes the Internet itself. IP Version 4 (IPv4) is the initial version used on the first generation of the today's Internet and is still in dominant use. It was designed to address up to ~4.3 billion (10⁹) Internet hosts. However, the explosive growth of the Internet has led to IPv4 address exhaustion which is estimated to enter its final stage in approximately 2011.^[9] A new protocol version, IPv6, was developed which provides vastly larger addressing capabilities and more efficient routing of Internet traffic. IPv6 is currently in commercial deployment phase around the world and Internet address registries (RIRs) have begun to urge all resource managers to plan rapid adoption and conversion.^[10]

IPv6 is not interoperable with IPv4. It essentially establishes a "parallel" version of the Internet not directly accessible with IPv4 software. This means software upgrades or translator facilities are necessary for every networking device that needs to communicate on the IPv6 Internet. Most modern computer operating systems are already converted to operate with both versions of the Internet Protocol. Network infrastructures, however, are still lagging in this development.

Aside from the complex physical connections that make up its infrastructure, the Internet is facilitated by bi- or multi-lateral commercial contracts (e.g., peering agreements), and by technical specifications or protocols that describe how to exchange data over the network. Indeed, the Internet is defined by its interconnections and routing policies.

Today's Internet

Internet structure

The Internet and its structure have been studied extensively. For example, it has been determined that both the Internet IP routing structure and hypertext links of the World Wide Web are examples of scale-free networks.

Similar to the way the commercial Internet providers connect via Internet exchange points, research networks tend to interconnect into large subnetworks such as GEANT, GLORIAD, Internet2 (successor of the Abilene Network), and the UK's national research and education network JANET. These in turn are built around smaller networks (see also the list of academic computer network organizations).

Many computer scientists describe the Internet as a "prime example of a large-scale, highly engineered, yet highly complex system".^[11] The Internet is extremely heterogeneous; for instance, data transfer rates and physical characteristics of connections vary widely. The Internet exhibits "emergent phenomena" that depend on its large-scale organization. For example, data transfer rates exhibit temporal self-similarity. Further adding to the complexity of the Internet is the ability of more than one computer to use the Internet through only one node, thus creating the possibility for a very deep and hierarchical sub-network that can theoretically be extended infinitely (disregarding the programmatic limitations of the IPv4 protocol). Principles of this architecture date back to the 1960s and it might not be a solution best suited to modern needs. Thus, the possibility of developing alternative structures is currently being looked into.^[12]

According to a June 2007 article in Discover magazine, the combined weight of all the electrons moved within the Internet in a day is 0.2 millionths of an ounce.^[13] Others have estimated this at nearer 2 ounces (50 grams).^[14]

Computer network diagrams often represent the Internet using a cloud symbol from which network communications pass in and out.^[15]

ICANN

ICANN headquarters in Marina Del Rey, California, United States

Main article: ICANN

The Internet Corporation for Assigned Names and Numbers (ICANN) is the authority that coordinates the assignment of unique identifiers on the Internet, including domain names, Internet Protocol (IP) addresses, and protocol port and parameter numbers. A globally unified name space (i.e., a system of names in which there is at most one holder for each possible name) is essential for the Internet to function. ICANN is headquartered in Marina del Rey, California, but is overseen by an international board of directors drawn from across the Internet technical, business, academic, and non-commercial communities. The US government continues to have the primary role in approving changes to the root zone file that lies at the heart of the domain name system. Because the Internet is a distributed network comprising many voluntarily interconnected networks, the Internet has no governing body. ICANN's role in coordinating the assignment of unique identifiers distinguishes it as perhaps the only central coordinating body on the global Internet, but the scope of its authority extends only to the Internet's systems of domain names, IP addresses, protocol ports and parameter numbers.

On November 16, 2005, the World Summit on the Information Society, held in Tunis, established the Internet Governance Forum (IGF) to discuss Internet-related issues.

Language

Further information: English on the Internet, Global Internet usage, and Unicode

The prevalent language for communication on the Internet is English. This may be a result of the origin of the Internet, as well as English's role as a lingua franca. It may also be related to the poor capability of early computers, largely originating in the United States, to handle characters other than those in the English variant of the Latin alphabet.

After English (28.6% of Web visitors) the most requested languages on the World Wide Web are Chinese (20.3%), Spanish (8.2%), Japanese (5.9%), French and Portuguese (4.6%), German (4.1%), Arabic (2.6%), Russian (2.4%), and Korean (2.3%).^[16]

By region, 41% of the world's Internet users are based in Asia, 25% in Europe, 16% in North America, 11% in Latin America and the Caribbean, 3% in Africa, 3% in the Middle East and 1% in Australia.^[17]

The Internet's technologies have developed enough in recent years, especially in the use of Unicode, that good facilities are available for development and communication in most widely used languages. However, some glitches such as mojibake (incorrect display of foreign language characters, also known as kryakozyabry) still remain.

Internet and the workplace

The Internet is allowing greater flexibility in working hours and location, especially with the spread of unmetered high-speed connections and Web applications.

The Internet viewed on mobile devices

The Internet can now be accessed virtually anywhere by numerous means. Mobile phones, datacards, handheld game consoles and cellular routers allow users to connect to the Internet from anywhere there is a cellular network supporting that device's technology.

Within the limitations imposed by the small screen and other limited facilities of such a pocket-sized device, all the services of the Internet, including email and web browsing, may be available in this way. Service providers may restrict the range of these services and charges for data access may be significant, compared to home usage.

Common uses

E-mail

Main article: E-mail

The concept of sending electronic text messages between parties in a way analogous to mailing letters or memos predates the creation of the Internet.

Today it can be important to distinguish between internet and internal e-mail systems. Internet e-mail may travel and be stored unencrypted on many other networks and machines out of both the sender's and the recipient's control. During this time it is quite possible for the content to be read and even tampered with by third parties, if anyone considers it important enough. Purely internal or intranet mail systems, where the information never leaves the corporate or organization's network, are much more secure, although in any organization there will be IT and other personnel whose job may involve monitoring, and occasionally accessing, the e-mail of other employees not addressed to them.

Pictures, documents and other files can be sent as e-mail attachments. E-mails can be cc-ed to multiple e-mail addresses.

The World Wide Web

Main article: World Wide Web

Graphic representation of a minute fraction of the WWW, demonstrating hyperlinks

Many people use the terms Internet and World Wide Web (or just the Web) interchangeably, but, as discussed above, the two terms are not synonymous.

The World Wide Web is a huge set of interlinked documents, images and other resources, linked by hyperlinks and URLs. These hyperlinks and URLs allow the web servers and other machines that store originals, and cached copies of, these resources to deliver them as required using HTTP (Hypertext Transfer Protocol). HTTP is only one of the communication protocols used on the Internet.

Web services also use HTTP to allow software systems to communicate in order to share and exchange business logic and data.

Software products that can access the resources of the Web are correctly termed user agents. In normal use, web browsers, such as Internet Explorer, Firefox, Opera, Apple Safari, and Google Chrome, access web pages and allow users to navigate from one to another via hyperlinks. Web documents may contain almost any combination of computer data including graphics, sounds, text, video, multimedia and interactive content including games, office applications and scientific demonstrations.

Through keyword-driven Internet research using search engines like Yahoo! and Google, millions of people worldwide have easy, instant access to a vast and diverse amount of online information. Compared to encyclopedias and traditional libraries, the World Wide Web has enabled a sudden and extreme decentralization of information and data.

Using the Web, it is also easier than ever before for individuals and organizations to publish ideas and information to an extremely large audience. Anyone can find ways to publish a web page, a blog or build a website for very little initial cost. Publishing and maintaining large, professional websites full of attractive, diverse and up-to-date information is still a difficult and expensive proposition, however.

Many individuals and some companies and groups use "web logs" or blogs, which are largely used as easily updatable online diaries. Some commercial organizations encourage staff to fill them with advice on their areas of specialization in the hope that visitors will be impressed by the expert knowledge and free information, and be attracted to the corporation as a result. One example of this practice is Microsoft, whose product developers publish their personal blogs in order to pique the public's interest in their work.

Collections of personal web pages published by large service providers remain popular, and have become increasingly sophisticated. Whereas operations such as Angelfire and GeoCities have existed since the early days of the Web, newer offerings from, for example, Facebook and MySpace currently have large followings. These operations often brand themselves as social network services rather than simply as web page hosts.

Advertising on popular web pages can be lucrative, and e-commerce or the sale of products and services directly via the Web continues to grow.

In the early days, web pages were usually created as sets of complete and isolated HTML text files stored on a web server. More recently, websites are more often created using content management or wiki software with, initially, very little content. Contributors to these systems, who may be paid staff, members of a club or other organization or members of the public, fill underlying databases with content using editing pages designed for that purpose, while casual visitors view and read this content in its final HTML form. There may or may not be editorial, approval and security systems built into the process of taking newly entered content and making it available to the target visitors.

Remote access

Main article: Remote access

The Internet allows computer users to connect to other computers and information stores easily, wherever they may be across the world. They may do this with or without the use of security, authentication and encryption technologies, depending on the requirements.

This is encouraging new ways of working from home, collaboration and information sharing in many industries. An accountant sitting at home can audit the books of a company based in another country, on a server situated in a third country that is remotely maintained by IT specialists in a fourth. These accounts could have been created by home-working bookkeepers, in other remote locations, based on information e-mailed to them from offices all over the world. Some of these things were possible before the widespread use of the Internet, but the cost of private leased lines would have made many of them infeasible in practice.

An office worker away from their desk, perhaps on the other side of the world on a business trip or a holiday, can open a remote desktop session into his normal office PC using a secure Virtual Private Network (VPN) connection via the Internet. This gives the worker complete access to all of his or her normal files and data, including e-mail and other applications, while away from the office.

This concept is also referred to by some network security people as the Virtual Private Nightmare, because it extends the secure perimeter of a corporate network into its employees' homes.

Collaboration

See also: Collaborative software

The low cost and nearly instantaneous sharing of ideas, knowledge, and skills has made collaborative work dramatically easier. Not only can a group cheaply communicate and share ideas, but the wide reach of the Internet allows such groups to easily form in the first place. An example of this is the free software movement, which has produced, among other programs, Linux, Mozilla Firefox, and OpenOffice.org.

Internet "chat", whether in the form of IRC chat rooms or channels, or via instant messaging systems, allow colleagues to stay in touch in a very convenient way when working at their computers during the day. Messages can be exchanged even more quickly and conveniently than via e-mail. Extensions to these systems may allow files to be exchanged, "whiteboard" drawings to be shared or voice and video contact between team members.

Version control systems allow collaborating teams to work on shared sets of documents without either accidentally overwriting each other's work or having members wait until they get "sent" documents to be able to make their contributions.

Business and project teams can share calendars as well as documents and other information. Such collaboration occurs in a wide variety of areas including scientific research, software development, conference planning, political activism and creative writing.

Social and political collaboration is also becoming more widespread as both Internet access and computer literacy grow. From the flash mob 'events' of the early 2000s to the use of social networking in the 2009 Iranian election protests, the Internet allows people to work together more effectively and in many more ways than was possible without it.

File sharing

Main article: File sharing

A computer file can be e-mailed to customers, colleagues and friends as an attachment. It can be uploaded to a website or FTP server for easy download by others. It can be put into a "shared location" or onto a file server for instant use by colleagues. The load of bulk downloads to many users can be eased by the use of "mirror" servers or peer-to-peer networks.

In any of these cases, access to the file may be controlled by user authentication, the transit of the file over the Internet may be obscured by encryption, and money may change hands for access to the file. The price can be paid by the remote charging of funds from, for example, a credit card whose details are also passed—usually fully encrypted—across the Internet. The origin and authenticity of the file received may be checked by digital signatures or by MD5 or other message digests.

These simple features of the Internet, over a worldwide basis, are changing the production, sale, and distribution of anything that can be reduced to a computer file for transmission. This includes all manner of print publications, software products, news, music, film, video, photography, graphics and the other arts. This in turn has caused seismic shifts in each of the existing industries that previously controlled the production and distribution of these products.

Streaming media

Many existing radio and television broadcasters provide Internet "feeds" of their live audio and video streams (for example, the BBC). They may also allow time-shift viewing or listening such as Preview, Classic Clips and Listen Again features. These providers have been joined by a range of pure Internet "broadcasters" who never had on-air licenses. This means that an Internet-connected device, such as a computer or something more specific, can be used to access on-line media in much the same way as was previously possible only with a television or radio receiver. The range of material is much wider, from pornography to highly specialized, technical webcasts. Podcasting is a variation on this theme, where—usually audio—material is downloaded and played back on a computer or shifted to a portable media player to be listened to on the move. These techniques using simple equipment allow anybody, with little censorship or licensing control, to broadcast audio-visual material on a worldwide basis.

Webcams can be seen as an even lower-budget extension of this phenomenon. While some webcams can give full-frame-rate video, the picture is usually either small or updates slowly. Internet users can watch animals around an African waterhole, ships in the Panama Canal, traffic at a local roundabout or monitor their own premises, live and in real time. Video chat rooms and video conferencing are also popular with many uses being found for personal webcams, with and without two-way sound.

YouTube was founded on 15 February 2005 and is now the leading website for free streaming video with a vast number of users. It uses a flash-based web player to stream and show video files. Registered users may upload an unlimited amount of video and build their own personal profile. YouTube claims that its users watch hundreds of millions, and upload hundreds of thousands, of videos daily.^[18]

Internet Telephony (VoIP)

Main article: VoIP

VoIP stands for Voice-over-Internet Protocol, referring to the protocol that underlies all Internet communication. The idea began in the early 1990s with walkie-talkie-like voice applications for personal computers. In recent years many VoIP systems have become as easy to use and as convenient as a normal telephone. The benefit is that, as the Internet carries the voice traffic, VoIP can be free or cost much less than a traditional telephone call, especially over long distances and especially for those with always-on Internet connections such as cable or ADSL.

VoIP is maturing into a competitive alternative to traditional telephone service. Interoperability between different providers has improved and the ability to call or receive a call from a traditional telephone is available. Simple, inexpensive VoIP network adapters are available that eliminate the need for a personal computer.

Voice quality can still vary from call to call but is often equal to and can even exceed that of traditional calls.

Remaining problems for VoIP include emergency telephone number dialling and reliability. Currently, a few VoIP providers provide an emergency service, but it is not universally available. Traditional phones are line-powered and operate during a power failure; VoIP does not do so without a backup power source for the phone equipment and the Internet access devices.

VoIP has also become increasingly popular for gaming applications, as a form of communication between players. Popular VoIP clients for gaming include Ventrilo and Teamspeak. Wii, PlayStation 3, and Xbox 360 also offer VoIP chat features.

Internet by region

Main articles: Internet access worldwide and List of countries by number of Internet users

Internet access

Main article: Internet access

Wikibooks has a book on the topic of Online linux connect

Common methods of home access include dial-up, landline broadband (over coaxial cable, fiber optic or copper wires), Wi-Fi, satellite and 3G technology cell phones.

Public places to use the Internet include libraries and Internet cafes, where computers with Internet connections are available. There are also Internet access points in many public places such as airport halls and coffee shops, in some cases just for brief use while standing. Various terms are used, such as "public Internet kiosk", "public access terminal", and "Web payphone". Many hotels now also have public terminals, though these are usually fee-based. These terminals are widely accessed for various usage like ticket booking, bank deposit, online payment etc. Wi-Fi provides wireless access to computer networks, and therefore can do so to the Internet itself. Hotspots providing such access include Wi-Fi cafes, where would-be users need to bring their own wireless-enabled devices such as a laptop or PDA. These services may be free to all, free to customers only, or fee-based. A hotspot need not be limited to a confined location. A whole campus or park, or even an entire city can be enabled. Grassroots efforts have led to wireless community networks. Commercial Wi-Fi services covering large city areas are in place in London, Vienna, Toronto, San Francisco, Philadelphia, Chicago and Pittsburgh. The Internet can then be accessed from such places as a park bench.^[19]

Apart from Wi-Fi, there have been experiments with proprietary mobile wireless networks like Ricochet, various high-speed data services over cellular phone networks, and fixed wireless services.

High-end mobile phones such as smartphones generally come with Internet access through the phone network. Web browsers such as Opera are available on these advanced handsets, which can also run a wide variety of other Internet software. More mobile phones have Internet access than PCs, though this is not as widely used. An Internet access provider and protocol matrix differentiates the methods used to get online.

Internet access
Network type	Wired					Wireless
	Optical	Coaxial cable	Ethernet cable	Phone line	Power line	Unlicensed terrestrial bands	Licensed terrestrial bands	Satellite
LAN	1000BASE-X	G.hn	Ethernet	HomePNA  · G.hn	G.hn	Wi-Fi · Bluetooth · DECT · Wireless USB
WAN	PON	DOCSIS		Dial-up · ISDN · DSL	BPL	Muni Wi-Fi	GPRS · iBurst · WiBro/WiMAX · UMTS-TDD, HSPA · EVDO · LTE	Satellite

Social impact

This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (November 2008)

See also: Sociology of the Internet

Chris Young was voted into the 2007 Major League Baseball All-Star Game on the Internet via the All-Star Final Vote.

The Internet has made possible entirely new forms of social interaction, activities and organizing, thanks to its basic features such as widespread usability and access.

Social networking websites such as Facebook and MySpace have created a new form of socialization and interaction. Users of these sites are able to add a wide variety of items to their personal pages, to indicate common interests, and to connect with others. It is also possible to find a large circle of existing acquaintances, especially if a site allows users to utilize their real names, and to allow communication among large existing groups of people.

Sites like meetup.com exist to allow wider announcement of groups which may exist mainly for face-to-face meetings, but which may have a variety of minor interactions over their group's site at meetup.org, or other similar sites.

Digital Natives

Main article: Born Digital

The first generation is now being raised with widespread availability of Internet connectivity, with consequences for privacy, identity, and copyright concerns. These "Digital Natives" face a variety of concerns that were not present for prior generations.

Political organization and censorship

For more details on this topic, see Internet censorship.

In democratic societies, the Internet has achieved new relevance as a political tool. The presidential campaign of Howard Dean in 2004 in the United States became famous for its ability to generate donations via the Internet. Many political groups use the Internet to achieve a whole new method of organizing, in order to carry out Internet activism.

Some governments, such as those of Iran, North Korea, Myanmar, the People's Republic of China, and Saudi Arabia, restrict what people in their countries can access on the Internet, especially political and religious content. This is accomplished through software that filters domains and content so that they may not be easily accessed or obtained without elaborate circumvention.

In Norway, Denmark, Finland^[20] and Sweden, major Internet service providers have voluntarily (possibly to avoid such an arrangement being turned into law) agreed to restrict access to sites listed by police. While this list of forbidden URLs is only supposed to contain addresses of known child pornography sites, the content of the list is secret.

Many countries, including the United States, have enacted laws making the possession or distribution of certain material, such as child pornography, illegal, but do not use filtering software.

There are many free and commercially available software programs with which a user can choose to block offensive websites on individual computers or networks, such as to limit a child's access to pornography or violence. See Content-control software.

Leisure activities

The Internet has been a major source of leisure since before the World Wide Web, with entertaining social experiments such as MUDs and MOOs being conducted on university servers, and humor-related Usenet groups receiving much of the main traffic. Today, many Internet forums have sections devoted to games and funny videos; short cartoons in the form of Flash movies are also popular. Over 6 million people use blogs or message boards as a means of communication and for the sharing of ideas.

The pornography and gambling industries have both taken full advantage of the World Wide Web, and often provide a significant source of advertising revenue for other websites. Although many governments have attempted to put restrictions on both industries' use of the Internet, this has generally failed to stop their widespread popularity.

One main area of leisure on the Internet is multiplayer gaming. This form of leisure creates communities, bringing people of all ages and origins to enjoy the fast-paced world of multiplayer games. These range from MMORPG to first-person shooters, from role-playing games to online gambling. This has revolutionized the way many people interact and spend their free time on the Internet.

While online gaming has been around since the 1970s, modern modes of online gaming began with services such as GameSpy and MPlayer, to which players of games would typically subscribe. Non-subscribers were limited to certain types of game play or certain games.

Many use the Internet to access and download music, movies and other works for their enjoyment and relaxation. As discussed above, there are paid and unpaid sources for all of these, using centralized servers and distributed peer-to-peer technologies. Some of these sources take more care over the original artists' rights and over copyright laws than others.

Many use the World Wide Web to access news, weather and sports reports, to plan and book holidays and to find out more about their random ideas and casual interests.

People use chat, messaging and e-mail to make and stay in touch with friends worldwide, sometimes in the same way as some previously had pen pals. Social networking websites like MySpace, Facebook and many others like them also put and keep people in contact for their enjoyment.

The Internet has seen a growing number of Web desktops, where users can access their files, folders, and settings via the Internet.

Cyberslacking has become a serious drain on corporate resources; the average UK employee spends 57 minutes a day surfing the Web at work, according to a study by Peninsula Business Services.^[21]

Market

Further information: Disintermediation#Impact of Internet-related disintermediation upon various industries and Travel agency#The Internet threat

The Internet has also become a large market for companies; some of the biggest companies today have grown by taking advantage of the efficient nature of low-cost advertising and commerce through the Internet, also known as e-commerce. It is the fastest way to spread information to a vast number of people simultaneously. The Internet has also subsequently revolutionized shopping—for example; a person can order a CD online and receive it in the mail within a couple of days, or download it directly in some cases. The Internet has also greatly facilitated personalized marketing which allows a company to market a product to a specific person or a specific group of people more so than any other advertising medium.

Examples of personalized marketing include online communities such as MySpace, Friendster, Orkut, Facebook and others which thousands of Internet users join to advertise themselves and make friends online. Many of these users are young teens and adolescents ranging from 13 to 25 years old. In turn, when they advertise themselves they advertise interests and hobbies, which online marketing companies can use as information as to what those users will purchase online, and advertise their own companies' products to those users.

See also

Internet portal

Main articles: Outline of the Internet and List of Internet topics

Wikipedia:Books has a book on: Internet

Find more about Internet on Wikipedia's sister projects: Definitions from Wiktionary

Textbooks from Wikibooks
Quotations from Wikiquote
Source texts from Wikisource
Images and media from Commons
News stories from Wikinews

Learning resources from Wikiversity

• List of inventions by the military that are now in mass use
• Demographics of the Internet
• Digital rights
• Internet democracy
• Network Neutrality
• Freedom of information
• Privacy on the Internet
• Internet phenomenon
• Internet bias
• List of cable Internet providers
• Electronic publishing

Notes

1. ^ "Links". HTML 4.01 Specification. World Wide Web Consortium. HTML 4.01 Specification. http://www.w3.org/TR/html401/struct/links.html#h-12.1. Retrieved on 2008-08-13. "[T]he link (or hyperlink, or Web link) [is] the basic hypertext construct. A link is a connection from one Web resource to another. Although a simple concept, the link has been one of the primary forces driving the success of the Web." 
2. ^ "ARPA/DARPA". Defense Advanced Research Projects Agency. http://www.darpa.mil/body/arpa_darpa.html. Retrieved on 2007-05-21. 
3. ^ "DARPA Over the Years". Defense Advanced Research Projects Agency. http://www.darpa.mil/body/overtheyears.html. Retrieved on 2007-05-21. 
4. ^ Baran, Paul (1964). On Distributed Communications. http://www.rand.org/pubs/research_memoranda/RM3767. 
5. ^ Coffman, K. G; Odlyzko, A. M. (1998-10-02) (PDF). The size and growth rate of the Internet. AT&T Labs. http://www.dtc.umn.edu/~odlyzko/doc/internet.size.pdf. Retrieved on 2007-05-21. 
6. ^ Comer, Douglas (2006). The Internet book. Prentice Hall. p. 64. ISBN 0132335530. 
7. ^ "AMD 50x15 - World Internet Usage". 50x15.com. http://www.50x15.com/en-us/internet_usage.aspx. Retrieved on 2009-06-20. 
8. ^ "IETF Home Page". Ietf.org. http://www.ietf.org/. Retrieved on 2009-06-20. 
9. ^ Huston, Geoff. "IPv4 Address Report, daily generated". http://www.potaroo.net/tools/ipv4/index.html. Retrieved on 2009-05-20. 
10. ^ Notice of Internet Protocol version 4 (IPv4) Address Depletion
11. ^ Walter Willinger, Ramesh Govindan, Sugih Jamin, Vern Paxson, and Scott Shenker (2002). Scaling phenomena in the Internet, in Proceedings of the National Academy of Sciences, 99, suppl. 1, 2573–2580
12. ^ "Internet Makeover? Some argue it's time". The Seattle Times, April 16, 2007.
13. ^ "How Much Does The Internet Weigh?". Discover Magazine, June 2007.
14. ^ "Weighing The Web". 2007-06-01. http://adamant.typepad.com/seitz/2007/06/the_sincerest_f.html. Retrieved on 2008-05-26. 
15. ^ The Internet Cloud
16. ^ Internet World Stats, updated December 31, 2008
17. ^ World Internet Usage Statistics News and Population Stats updated December 31, 2008
18. ^ "YouTube Fact Sheet". YouTube, LLC. http://www.youtube.com/t/fact_sheet. Retrieved on 2009-01-20. 
19. ^ "Toronto Hydro to Install Wireless Network in Downtown Toronto". Bloomberg.com. Retrieved 19-Mar-2006.
20. ^ "Finland censors anti-censorship site". The Register. 2008-02-18. http://www.theregister.co.uk/2008/02/18/finnish_policy_censor_activist/. Retrieved on 2008-02-19. 
21. ^ Scotsman.com News - Net abuse hits small city firms

References

• Media Freedom Internet Cookbook by the OSCE Representative on Freedom of the Media Vienna, 2004
• Living Internet—Internet history and related information, including information from many creators of the Internet
• First Monday peer-reviewed journal on the Internet
• How Much Does The Internet Weigh? by Stephen Cass, Discover 2007
• Rehmeyer, Julie J. 2007. Mapping a medusa: The Internet spreads its tentacles. Science News 171(June 23):387-388. Available at http://www.sciencenews.org/articles/20070623/fob2.asp .
• Castells, M. 1996. Rise of the Network Society. 3 vols. Vol. 1. Cambridge, MA: Blackwell Publishers.
• Castells, M. (2001), “Lessons from the History of Internet”, in “The Internet Galaxy”, Ch. 1, pp 9–35. Oxford Univ. Press.
• RFC 1122, Requirements for Internet Hosts—Communication Layers, IETF, R. Braden (Ed.), October 1989
• RFC 1123, Requirements for Internet Hosts—Application and Support, IETF, R. Braden (Ed.), October 1989

External links

• The Internet (National Science Foundation)
• "10 Years that changed the world" — Wired looks back at the evolution of the Internet over last 10 years
• Berkman Center for Internet and Society at Harvard
• CBC Digital Archives—Inventing the Internet Age
• How the Internet Came to Be
• The Internet Society History Page
• RFC 801, planning the TCP/IP switchover
• Preparing Europe’s digital future - i2010 Mid-Term Review
• Manjoo, Farhad - The Unrecognizable Internet of 1996 - Slate

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)

Dansk (Danish)
abbr. - Nettet
n. - Internet

idioms:

• internet protocol address    Internet protokol adresse

Nederlands (Dutch)
Internet

Français (French)
abbr. - réseau Internet
n. - Internet

idioms:

• internet protocol address    adresse de protocole Internet

Deutsch (German)
abbr. - Internationales Computernetz
n. - (Comp.) Internet (internationales Computernetz)

idioms:

• internet protocol address    Protokoll für Netzwerkschnittstellen

Ελληνική (Greek)
n. - Διαδίκτυο

idioms:

• internet protocol address    διεύθυνση πρωτοκόλλου του Διαδικτύου

Italiano (Italian)
Internet

Português (Portuguese)
abbr. - Rede (f) Internacional
n. - Internet (f)

Русский (Russian)
интернет

Español (Spanish)
abbr. - Internet
n. - Internet

idioms:

• internet protocol address    dirección de protocolo de Internet

Svenska (Swedish)
abbr. - internetwork
n. - internet

中文（简体）(Chinese (Simplified))
因特网, 国际互联网络

idioms:

• internet protocol address    由四个数字所组成的一组数字, 定义着网络上的每一节点

中文（繁體）(Chinese (Traditional))
abbr. - 網際網路
n. - 網際網路

idioms:

• internet protocol address    由四個數字所組成的一組數字, 定義著網路上的每一節點

한국어 (Korean)
abbr. - 인터넷
n. - 인터넷

日本語 (Japanese)
n. - インターネット

العربيه (Arabic)
‏(الاسم) شبكه الإنترنت‏

עברית (Hebrew)
abbr. - ‮אינטרנט, רשת תקשורת אלקטרונית בילאומית‬
n. - ‮אינטרנט, רשת תקשורת אלקטרונית בילאומית‬

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