Internet

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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.

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.

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

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.

An Open Book

From our Archives: Today's Highlights, January 21, 2009

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.

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

• Internet and World Wide Web - Internet: global network for communication of data among computers and smaller networks using the TCP/IP protocols

Internet
Routing paths through a portion of the Internet as visualized by the Opte Project
General
Access · Censorship
Digital divide · Digital rights
Freedom of information · History
Usage · Democracy
Internet phenomenon · Privacy
Net neutrality · Sociology
Internet governance
Internet Corporation for Assigned Names and Numbers (ICANN)
Internet Engineering Task Force (IETF)
Internet Governance Forum (IGF)
Internet Society (ISOC)
Protocols and infrastructure
Domain Name System (DNS)
Hypertext Transfer Protocol (HTTP)
IP address · Internet exchange point
Internet Protocol (IP)
Internet Protocol Suite (TCP/IP)
Internet service provider (ISP)
Simple Mail Transfer Protocol (SMTP)
Services
Blogs · Microblogs · E-mail
Fax · File sharing · File transfer
Instant messaging · Gaming
TV · Podcast · Search
Voice over IP (VoIP)
World Wide Web
Guides
Outline · Topics
Internet portal This box: view talk edit

Computer network types by geographical scope
Near field (NFC) Body (BAN) Personal (PAN) Near-me (NAN) Local (LAN) Home (HAN) Storage (SAN) Campus (CAN) Backbone Metropolitan (MAN) Wide (WAN) Internet Interplanetary Internet
v t e

This article is about the public worldwide computer network system. For other uses, see Internet (disambiguation).

The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite (often called TCP/IP, although not all applications use TCP) to serve billions of users worldwide. It is a network of networks that consists of millions of private, public, academic, business, and government networks, of local to global scope, that are linked by a broad array of electronic, wireless and optical networking technologies. The Internet carries an extensive range of information resources and services, such as the inter-linked hypertext documents of the World Wide Web (WWW) and the infrastructure to support email.

Most traditional communications media including telephone, music, film, and television are reshaped or redefined by the Internet, giving birth to new services such as Voice over Internet Protocol (VoIP) and Internet Protocol Television (IPTV). Newspaper, book and other print publishing are adapting to Web site technology, or are reshaped into blogging and web feeds. The Internet has enabled and accelerated new forms of human interactions through instant messaging, Internet forums, and social networking. Online shopping has boomed both for major retail outlets and small artisans and traders. Business-to-business and financial services on the Internet affect supply chains across entire industries.

The origins of the Internet reach back to research of the 1960s, commissioned by the United States government in collaboration with private commercial interests to build robust, fault-tolerant, and distributed computer networks. The funding of a new U.S. backbone by the National Science Foundation in the 1980s, as well as private funding for other commercial backbones, led to worldwide participation in the development of new networking technologies, and the merger of many networks. The commercialization of what was by the 1990s an international network resulted in its popularization and incorporation into virtually every aspect of modern human life. As of 2011, more than 2.2 billion people – nearly a third of Earth's population — use the services of the Internet.^[1]

The Internet has no centralized governance in either technological implementation or policies for access and usage; each constituent network sets its own standards. Only the overreaching definitions of the two principal name spaces in the Internet, the Internet Protocol address space and the Domain Name System, are directed by a maintainer organization, the Internet Corporation for Assigned Names and Numbers (ICANN). The technical underpinning and standardization of the core protocols (IPv4 and IPv6) is an activity of the Internet Engineering Task Force (IETF), a non-profit organization of loosely affiliated international participants that anyone may associate with by contributing technical expertise.

Contents 1 Terminology 2 History 3 Technology 3.1 Protocols 3.2 Routing 3.3 General structure 4 Governance 5 Modern uses 6 Services 6.1 Information 6.2 Communication 6.3 Data transfer 7 Access 8 Users 9 Social impact 9.1 Social networking and entertainment 9.2 Politics and political revolutions 9.3 Philanthropy 9.4 Censorship 10 See also 11 References 12 External links 12.1 Organizations 12.2 Articles, books, and journals

Terminology

See also: Internet capitalization conventions

Internet is a short form of the technical term internetwork,^[2] the result of interconnecting computer networks with special gateways or routers. The Internet is also often referred to as the Net.

The term the Internet, when referring to the entire global system of IP networks, has been treated as a proper noun and written with an initial capital letter. In the media and popular culture, a trend has also developed to regard it as a generic term or common noun and thus write it as "the internet", without capitalization. Some guides specify that the word should be capitalized as a noun but not capitalized as an adjective.^[3][4]

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 establishes a global data communications system 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.^[5] In addition to the Web, the Internet also powers a multitude of other services, including (among others) email, file transfer, newsgroups, and online games. On the flip side, Web services can exist apart from the internet, such as on a private intranet.

History

Professor Leonard Kleinrock with the first ARPANET Interface Message Processors at UCLA

Main articles: History of the Internet and History of the World Wide Web

Research into packet switching started in the early 1960s and packet switched networks such as ARPANET, Mark I at NPL in the UK,^[6] CYCLADES,^[7][8] Merit Network,^[9] Tymnet, and Telenet, were developed in the late 1960s and early 1970s using a variety of protocols. The ARPANET in particular led to the development of protocols for internetworking, where multiple separate networks could be joined together into a network of networks.

The first two nodes of what would become the ARPANET were interconnected between Leonard Kleinrock's Network Measurement Center at the UCLA's School of Engineering and Applied Science and Douglas Engelbart's NLS system at SRI International (SRI) in Menlo Park, California, on 29 October 1969.^[10] The third site on the ARPANET was the Culler-Fried Interactive Mathematics center at the University of California at Santa Barbara, and the fourth was the University of Utah Graphics Department. In an early sign of future growth, there were already fifteen sites connected to the young ARPANET by the end of 1971.^[11][12] These early years were documented in the 1972 film Computer Networks: The Heralds of Resource Sharing.

Early international collaborations on ARPANET were sparse. For various political reasons, European developers were concerned with developing the X.25 networks.^[13] Notable exceptions were the Norwegian Seismic Array (NORSAR) in 1972, followed in 1973 by Sweden with satellite links to the Tanum Earth Station and Peter T. Kirstein's research group in the UK, initially at the Institute of Computer Science, London University and later at University College London.^[14]

T3 NSFNET Backbone, c. 1992

In 1982, the Internet Protocol Suite (TCP/IP) was standardized and the concept of a world-wide network of fully interconnected TCP/IP networks called the Internet was introduced. Access to the ARPANET was expanded in 1981 when the National Science Foundation (NSF) developed the Computer Science Network (CSNET). In December 1974, RFC 675 – Specification of Internet Transmission Control Program, by Vinton Cerf, Yogen Dalal, and Carl Sunshine, used the term internet, as a shorthand for internetworking; later RFCs repeat this use, so the word started out as an adjective rather than the noun it is today.^[15]

TCP/IP network access expanded again in 1986 when NSFNET provided access to supercomputer sites in the United States from research and education organizations, first at 56 kbit/s and later at 1.5 Mbit/s and 45 Mbit/s.^[16] Commercial internet service providers (ISPs) began to emerge in the late 1980s and 1990s. The ARPANET was decommissioned in 1990. The Internet was commercialized in 1995 when NSFNET was decommissioned, removing the last restrictions on the use of the Internet to carry commercial traffic.^[17] The Internet started a rapid expansion to Europe and Australia in the mid to late 1980s^[18][19] and to Asia in the late 1980s and early 1990s.^[20]

This NeXT Computer was used by Sir Tim Berners-Lee at CERN and became the world's first Web server.

Since the mid-1990s the Internet has had a tremendous impact on culture and commerce, including the rise of near instant communication by email, instant messaging, Voice over Internet Protocol (VoIP) "phone calls", two-way interactive video calls, and the World Wide Web^[21] with its discussion forums, blogs, social networking, and online shopping sites. Increasing amounts of data are transmitted at higher and higher speeds over fiber optic networks operating at 1-Gbit/s, 10-Gbit/s, or more. The Internet continues to grow, driven by ever greater amounts of online information and knowledge, commerce, entertainment and social networking.^[22]

During the late 1990s, it was estimated that traffic on the public Internet grew by 100 percent per year, while the mean annual growth in the number of Internet users was thought to be between 20% and 50%.^[23] 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.^[24] As of 31 March 2011, the estimated total number of Internet users was 2.095 billion (30.2% of world population).^[25] It is estimated that in 1993 the Internet carried only 1% of the information flowing through two-way telecommunication, by 2000 this figure had grown to 51%, and by 2007 more than 97% of all telecommunicated information was carried over the Internet.^[26]

Technology

Protocols

Main article: Internet protocol suite

As the user data is processed down through the protocol stack, each layer adds an encapsulation at the sending host. Data is transmitted "over the wire" at the link level, left to right. The encapsulation stack procedure is reversed by the receiving host. Intermediate relays remove and add a new link encapsulation for retransmission, and inspect the IP layer for routing purposes.

Internet protocol suite
Application layer
DHCP DHCPv6 DNS FTP HTTP IMAP IRC LDAP MGCP NNTP BGP OSPF NTP POP RPC RTP RTSP RIP SIP SMTP SNMP SOCKS SSH Telnet TLS/SSL XMPP (more)
Transport layer
TCP UDP DCCP SCTP RSVP (more)
Internet layer
IP IPv4 IPv6 ICMP ICMPv6 ECN IGMP IPsec (more)
Link layer
ARP/InARP NDP Tunnels L2TP PPP Media access control Ethernet DSL ISDN FDDI (more)
v t e

The 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).^[27] 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 called a Request for Comments (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. Other less rigorous documents are simply informative, experimental, or historical, or document the best current practices (BCP) when implementing Internet technologies.

The Internet 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. Below this top layer, the transport layer connects applications on different hosts via the network (e.g., client–server model) with appropriate data exchange methods. Underlying these layers are the core 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. Last, at the bottom of the architecture, is a software layer, the link layer, that provides connectivity between hosts on the same local network link, 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 or implementation; 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 in essence establishes the Internet itself. IP Version 4 (IPv4) is the initial version used on the first generation of 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 entered its final stage in 2011,^[28] when the global address allocation pool was exhausted. A new protocol version, IPv6, was developed in the mid-1990s, which provides vastly larger addressing capabilities and more efficient routing of Internet traffic. IPv6 is currently in growing deployment around the world, since Internet address registries (RIRs) began to urge all resource managers to plan rapid adoption and conversion.^[29]

IPv6 is not interoperable with IPv4. In essence, it establishes a parallel version of the Internet not directly accessible with IPv4 software. This means software upgrades or translator facilities are necessary for networking devices that need to communicate on both networks. Most modern computer operating systems already support both versions of the Internet Protocol. Network infrastructures, however, are still lagging in this development. Aside from the complex array of 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.

Routing

Internet packet routing is accomplished among various tiers of Internet Service Providers.

Internet Service Providers connect customers (thought of at the "bottom" of the routing hierarchy) to customers of other ISPs. At the "top" of the routing hierarchy are ten or so Tier 1 networks, large telecommunication companies which exchange traffic directly "across" to all other Tier 1 networks via unpaid peering agreements. Tier 2 networks buy Internet transit from other ISP to reach at least some parties on the global Internet, though they may also engage in unpaid peering (especially for local partners of a similar size). ISPs can use a single "upstream" provider for connectivity, or use multihoming to provide protection from problems with individual links. Internet exchange points create physical connections between multiple ISPs, often hosted in buildings owned by independent third parties.^{[citation needed]}

Computers and routers use routing tables to direct IP packets among locally connected machines. Tables can be constructed manually or automatically via DHCP for an individual computer or a routing protocol for routers themselves. In single-homed situations, a default route usually points "up" toward an ISP providing transit. Higher-level ISPs use the Border Gateway Protocol to sort out paths to any given range of IP addresses across the complex connections of the global Internet.^{[citation needed]}

Academic institutions, large companies, governments, and other organizations can perform the same role as ISPs, engaging in peering and purchasing transit on behalf of their internal networks of individual computers. Research networks tend to interconnect into large subnetworks such as GEANT, GLORIAD, Internet2, and the UK's national research and education network, JANET. These in turn are built around smaller networks (see the list of academic computer network organizations).^{[citation needed]}

Not all computer networks are connected to the Internet. For example, some classified United States websites are only accessible from separate secure networks.^{[citation needed]}

General structure

The Internet structure and its usage characteristics have been studied extensively. 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.^[30]

Many computer scientists describe the Internet as a "prime example of a large-scale, highly engineered, yet highly complex system".^[31] The Internet is 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. The principles of the routing and addressing methods for traffic in the Internet reach back to their origins in the 1960s when the eventual scale and popularity of the network could not be anticipated. Thus, the possibility of developing alternative structures is investigated.^[32] The Internet structure was found to be highly robust^[33] to random failures and very vulnerable to high degree attacks.^[34]

Governance

Main article: Internet governance

ICANN headquarters in Marina Del Rey, California, United States

The Internet is a globally distributed network comprising many voluntarily interconnected autonomous networks. It operates without a central governing body. However, to maintain interoperability, all technical and policy aspects of the underlying core infrastructure and the principal name spaces are administered by the Internet Corporation for Assigned Names and Numbers (ICANN), headquartered in Marina del Rey, California. ICANN is the authority that coordinates the assignment of unique identifiers for use on the Internet, including domain names, Internet Protocol (IP) addresses, application port numbers in the transport protocols, and many other parameters. Globally unified name spaces, in which names and numbers are uniquely assigned, are essential for the global reach of the Internet. ICANN is governed by an international board of directors drawn from across the Internet technical, business, academic, and other non-commercial communities. The government of the United States continues to have the primary role in approving changes to the DNS root zone that lies at the heart of the domain name system.^[35] ICANN's role in coordinating the assignment of unique identifiers distinguishes it as perhaps the only central coordinating body on the global Internet. On 16 November 2005, the World Summit on the Information Society, held in Tunis, established the Internet Governance Forum (IGF) to discuss Internet-related issues.

Modern uses

The Internet allows greater flexibility in working hours and location, especially with the spread of unmetered high-speed connections. The Internet can be accessed almost anywhere by numerous means, including through mobile Internet devices. Mobile phones, datacards, handheld game consoles and cellular routers allow users to connect to the Internet wirelessly. Within the limitations imposed by small screens and other limited facilities of such pocket-sized devices, the services of the Internet, including email and the web, may be available. Service providers may restrict the services offered and mobile data charges may be significantly higher than other access methods.

Educational material at all levels from pre-school to post-doctoral is available from websites. Examples range from CBeebies, through school and high-school revision guides, virtual universities, to access to top-end scholarly literature through the likes of Google Scholar. For distance education, help with homework and other assignments, self-guided learning, whiling away spare time, or just looking up more detail on an interesting fact, it has never been easier for people to access educational information at any level from anywhere. The Internet in general and the World Wide Web in particular are important enablers of both formal and informal education.

The low cost and nearly instantaneous sharing of ideas, knowledge, and skills has made collaborative work dramatically easier, with the help of collaborative software. Not only can a group cheaply communicate and share ideas but the wide reach of the Internet allows such groups more easily to form. An example of this is the free software movement, which has produced, among other things, Linux, Mozilla Firefox, and OpenOffice.org. Internet chat, whether in the form of an IRC chat room or channel, via an instant messaging system, or a social networking website, allows 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 email. These systems may allow files to be exchanged, drawings and images to be shared, or voice and video contact between team members.

Content management systems allow collaborating teams to work on shared sets of documents simultaneously without accidentally destroying each other's work. 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 spread.

The Internet allows computer users to remotely access other computers and information stores easily, wherever they may be. They may do this with or without computer security, i.e. 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 emailed 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 access their emails, access their data using cloud computing, or open a remote desktop session into their office PC using a secure Virtual Private Network (VPN) connection on the Internet. This can give the worker complete access to all of their normal files and data, including email and other applications, while away from the office. This concept has been referred to among system administrators as the Virtual Private Nightmare,^[36] because it extends the secure perimeter of a corporate network into remote locations and its employees' homes.

Services

Information

Many people use the terms Internet and World Wide Web, or just the Web, interchangeably, but the two terms are not synonymous. The World Wide Web is a global set of documents, images and other resources, logically interrelated by hyperlinks and referenced with Uniform Resource Identifiers (URIs). URIs symbolically identify services, servers, and other databases, and the documents and resources that they can provide. Hypertext Transfer Protocol (HTTP) is the main access protocol of the World Wide Web, but it is only one of the hundreds of 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.

World Wide Web browser software, such as Microsoft's Internet Explorer, Mozilla Firefox, Opera, Apple's Safari, and Google Chrome, lets users navigate from one web page to another via hyperlinks embedded in the documents. These documents may also contain any combination of computer data, including graphics, sounds, text, video, multimedia and interactive content that runs while the user is interacting with the page. Client-side software can include animations, games, office applications and scientific demonstrations. Through keyword-driven Internet research using search engines like Yahoo! and Google, users worldwide have easy, instant access to a vast and diverse amount of online information. Compared to printed media, books, encyclopedias and traditional libraries, the World Wide Web has enabled the decentralization of information on a large scale.

The Web has also enabled individuals and organizations to publish ideas and information to a potentially large audience online at greatly reduced expense and time delay. Publishing a web page, a blog, or building a website involves little initial cost and many cost-free services are available. Publishing and maintaining large, professional web sites with 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 communicate advice in 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 Twitter 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.

When the Web began in the 1990s, a typical web page was stored in completed form on a web server, formatted in HTML, ready to be sent to a user's browser in response to a request. Over time, the process of creating and serving web pages has become more automated and more dynamic. Websites are 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.

Communication

Email is an important communications service available on the Internet. The concept of sending electronic text messages between parties in a way analogous to mailing letters or memos predates the creation of the Internet. Pictures, documents and other files are sent as email attachments. Emails can be cc-ed to multiple email addresses.

Internet telephony is another common communications service made possible by the creation of the Internet. 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 dialing 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.

Data transfer

File sharing is an example of transferring large amounts of data across the Internet. A computer file can be emailed 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 is the real-time delivery of digital media for the immediate consumption or enjoyment by end users. Many radio and television broadcasters provide Internet feeds of their live audio and video productions. 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 available types of content is much wider, from specialized technical webcasts to on-demand popular multimedia services. 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 worldwide.

Digital media streaming increases the demand for network bandwidth. For example, standard image quality needs 1 Mbit/s link speed for SD 480p, HD 720p quality requires 2.5 Mbit/s, and the top-of-the-line HDX quality needs 4.5 Mbit/s for 1080p.^[37]

Webcams are a low-cost extension of this phenomenon. While some webcams can give full-frame-rate video, the picture either is usually 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.^[38]

Access

Main article: Internet access

Common methods of Internet access in homes include dial-up, landline broadband (over coaxial cable, fiber optic or copper wires), Wi-Fi, satellite and 3G/4G 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.^[39] 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 in general 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.^[40] An Internet access provider and protocol matrix differentiates the methods used to get online.

An Internet blackout or outage can be caused by local signaling interruptions. Disruptions of submarine communications cables may cause blackouts or slowdowns to large areas, such as in the 2008 submarine cable disruption. Less-developed countries are more vulnerable due to a small number of high-capacity links. Land cables are also vulnerable, as in 2011 when a woman digging for scrap metal severed most connectivity for the nation of Armenia.^[41] Internet blackouts affecting almost entire countries can be achieved by governments as a form of Internet censorship, as in the blockage of the Internet in Egypt, whereby approximately 93%^[42] of networks were without access in 2011 in an attempt to stop mobilization for anti-government protests.^[43]

Users

Internet users per 100 inhabitants    Source: ITU^[44]

Internet users by language^[45]

Website content languages^[46]

See also: Global Internet usage, English on the Internet, and Unicode

Overall Internet usage has seen tremendous growth. From 2000 to 2009, the number of Internet users globally rose from 394 million to 1.858 billion.^[47] By 2010, 22 percent of the world's population had access to computers with 1 billion Google searches every day, 300 million Internet users reading blogs, and 2 billion videos viewed daily on YouTube.^[48]

The prevalent language for communication on the Internet has been English. This may be a result of the origin of the Internet, as well as the language's role as a lingua franca. Early computer systems were limited to the characters in the American Standard Code for Information Interchange (ASCII), a subset of the Latin alphabet.

After English (27%), the most requested languages on the World Wide Web are Chinese (23%), Spanish (8%), Japanese (5%), Portuguese and German (4% each), Arabic, French and Russian (3% each), and Korean (2%).^[49] By region, 42% of the world's Internet users are based in Asia, 24% in Europe, 14% in North America, 10% in Latin America and the Caribbean taken together, 6% in Africa, 3% in the Middle East and 1% in Australia/Oceania.^[50] 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 the world's widely used languages. However, some glitches such as mojibake (incorrect display of some languages' characters) still remain.

In an American study in 2005, the percentage of men using the Internet was very slightly ahead of the percentage of women, although this difference reversed in those under 30. Men logged on more often, spent more time online, and were more likely to be broadband users, whereas women tended to make more use of opportunities to communicate (such as email). Men were more likely to use the Internet to pay bills, participate in auctions, and for recreation such as downloading music and videos. Men and women were equally likely to use the Internet for shopping and banking.^[51] More recent studies indicate that in 2008, women significantly outnumbered men on most social networking sites, such as Facebook and Myspace, although the ratios varied with age.^[52] In addition, women watched more streaming content, whereas men downloaded more.^[53] In terms of blogs, men were more likely to blog in the first place; among those who blog, men were more likely to have a professional blog, whereas women were more likely to have a personal blog.^[54]

Social impact

Main article: Sociology of the Internet

The Internet has enabled entirely new forms of social interaction, activities, and organizing, thanks to its basic features such as widespread usability and access. In the first decade of the 21st century, the first generation is raised with widespread availability of Internet connectivity, bringing consequences and concerns in areas such as personal privacy and identity, and distribution of copyrighted materials. These "digital natives" face a variety of challenges that were not present for prior generations.

Social networking and entertainment

See also: Social networking service#Social impact

Many people use the World Wide Web to access news, weather and sports reports, to plan and book vacations and to find out more about their interests. People use chat, messaging and email to make and stay in touch with friends worldwide, sometimes in the same way as some previously had pen pals. The Internet has seen a growing number of Web desktops, where users can access their files and settings via the Internet.

Social networking websites such as Facebook, Twitter, and MySpace have created new ways to socialize and interact. Users of these sites are able to add a wide variety of information to pages, to pursue common interests, and to connect with others. It is also possible to find existing acquaintances, to allow communication among existing groups of people. Sites like LinkedIn foster commercial and business connections. YouTube and Flickr specialize in users' videos and photographs.

The Internet has been a major outlet for leisure activity since its inception, with entertaining social experiments such as MUDs and MOOs being conducted on university servers, and humor-related Usenet groups receiving much 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 taken advantage of the World Wide Web, and often provide a significant source of advertising revenue for other websites.^[55] Although many governments have attempted to restrict both industries' use of the Internet, in general this has failed to stop their widespread popularity.^[56]

Another area of leisure activity on the Internet is multiplayer gaming.^[57] This form of recreation creates communities, where people of all ages and origins enjoy the fast-paced world of multiplayer games. These range from MMORPG to first-person shooters, from role-playing video games to online gambling. While online gaming has been around since the 1970s, modern modes of online gaming began with subscription services such as GameSpy and MPlayer.^[58] Non-subscribers were limited to certain types of game play or certain games. Many people use the Internet to access and download music, movies and other works for their enjoyment and relaxation. Free and fee-based services exist for all of these activities, using centralized servers and distributed peer-to-peer technologies. Some of these sources exercise more care with respect to the original artists' copyrights than others.

Internet usage has been correlated to users' loneliness.^[59] Lonely people tend to use the Internet as an outlet for their feelings and to share their stories with others, such as in the "I am lonely will anyone speak to me" thread.

Cybersectarianism is a new organizational form which involves: "highly dispersed small groups of practitioners that may remain largely anonymous within the larger social context and operate in relative secrecy, while still linked remotely to a larger network of believers who share a set of practices and texts, and often a common devotion to a particular leader. Overseas supporters provide funding and support; domestic practitioners distribute tracts, participate in acts of resistance, and share information on the internal situation with outsiders. Collectively, members and practitioners of such sects construct viable virtual communities of faith, exchanging personal testimonies and engaging in collective study via email, on-line chat rooms and web-based message boards."^[60]

Cyberslacking can become a drain on corporate resources; the average UK employee spent 57 minutes a day surfing the Web while at work, according to a 2003 study by Peninsula Business Services.^[61] Internet addiction disorder is excessive computer use that interferes with daily life. Psychologist Nicolas Carr believe that Internet use has other effects on individuals, for instance improving skills of scan-reading and interfering with the deep thinking that leads to true creativity.^[62]

Politics and political revolutions

The Internet has achieved new relevance as a political tool. The presidential campaign of Howard Dean in 2004 in the United States was notable for its success in soliciting donation via the Internet. Many political groups use the Internet to achieve a new method of organizing in order to carry out their mission, having given rise to Internet activism, most notably practiced by rebels in the Arab Spring.^[63][64]

The New York Times suggested that social media websites such as Facebook and Twitter helped people organize the political revolutions in Egypt where it helped certain classes of protesters organize protests, communicate grievances, and disseminate information.^[65]

The potential of the Internet as a civic tool of communicative power was thoroughly explored by Simon R. B. Berdal in his thesis of 2004:

“

As the globally evolving Internet provides ever new access points to virtual discourse forums, it also promotes new civic relations and associations within which communicative power may flow and accumulate. Thus, traditionally ... national-embedded peripheries get entangled into greater, international peripheries, with stronger combined powers... The Internet, as a consequence, changes the topology of the "centre-periphery" model, by stimulating conventional peripheries to interlink into "super-periphery" structures, which enclose and "besiege" several centres at once.[66]

”

Berdal, therefore, extends the Habermasian notion of the Public sphere to the Internet, and underlines the inherent global and civic nature that intervowen Internet technologies provide. To limit the growing civic potential of the Internet, Berdal also notes how "self-protective measures" are put in place by those threatened by it:

“

If we consider China’s attempts to filter "unsuitable material" from the Internet, most of us would agree that this resembles a self-protective measure by the system against the growing civic potentials of the Internet. Nevertheless, both types represent limitations to "peripheral capacities". Thus, the Chinese government tries to prevent communicative power to build up and unleash (as the 1989 Tiananmen Square uprising suggests, the government may find it wise to install "upstream measures"). Even though limited, the Internet is proving to be an empowering tool also to the Chinese periphery: Analysts believe that Internet petitions have influenced policy implementation in favour of the public’s online-articulated will ...[66]

”

Philanthropy

The spread of low-cost internet access in developing countries has opened up new possibilities for peer-to-peer charities, which allow individuals to contribute small amounts to charitable projects for other individuals. Websites such as DonorsChoose and GlobalGiving allow small-scale donors to direct funds to individual projects of their choice.

A popular twist on internet-based philanthropy is the use of peer-to-peer lending for charitable purposes. Kiva pioneered this concept in 2005, offering the first web-based service to publish individual loan profiles for funding. Kiva raises funds for local intermediary microfinance organizations which post stories and updates on behalf of the borrowers. Lenders can contribute as little as $25 to loans of their choice, and receive their money back as borrowers repay. Kiva falls short of being a pure peer-to-peer charity, in that loans are disbursed before being funded by lenders and borrowers do not communicate with lenders themselves.^[67][68]

However, the recent spread of cheap internet access in developing countries has made genuine international person-to-person philanthropy increasingly feasible. In 2009 the US-based nonprofit Zidisha tapped into this trend to offer the first person-to-person microfinance platform to link lenders and borrowers across international borders without intermediaries. Inspired by interactive websites such as Facebook and eBay, Zidisha facilitates direct dialogue and microlending transactions between individual web users worldwide and computer-literate, low-income entrepreneurs in developing countries. Zidisha members can fund loans for as little as a dollar, which the borrowers then use to develop business activities that improve their families' incomes while repaying loans to the members with interest. Zidisha borrowers access the internet via public cybercafes, donated laptops in village schools, and even smart phones, then create their own profile pages through which they share photos and information about themselves and their businesses. As they repay their loans, borrowers continue to share updates and dialogue with lenders via their profile pages. This direct web-based connection allows Zidisha members themselves to take on many of the communication and recording tasks traditionally performed by local organizations, bypassing geographic barriers and dramatically reducing the cost of microfinance services to the entrepreneurs.^[69]

Censorship

Main articles: Internet censorship and Internet freedom

Some governments, such as those of Iran, North Korea, Burma, 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.^[70]

In Norway, Denmark, Finland, 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 authorities. While this list of forbidden URLs is supposed to contain addresses of only known child pornography sites, the content of the list is secret.^[71] Many countries, including the United States, have enacted laws against the possession or distribution of certain material, such as child pornography, via the Internet, but do not mandate filtering software. There are many free and commercially available software programs, called content-control software, with which a user can choose to block offensive websites on individual computers or networks, in order to limit a child's access to pornographic materials or depiction of violence.

See also

Internet portal

• Outline of the Internet
• Index of Internet-related articles

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62. ^ The Shallows: What the Internet Is Doing to Our Brains, Nicholas Carr, W. W. Norton, 7 June 2010, 276 pp., ISBN 0-393-07222-3, ISBN 978-0-393-07222-8
63. ^ "The Arab Uprising's Cascading Effects". Miller-mccune.com. 23 February 2011. http://www.miller-mccune.com/politics/the-cascading-effects-of-the-arab-spring-28575/. Retrieved 27 February 2011. 
64. ^ The Role of the Internet in Democratic Transition: Case Study of the Arab Spring, Davit Chokoshvili, Master's Thesis, June 2011
65. ^ Kirkpatrick, David D. (9 February 2011). "Wired and Shrewd, Young Egyptians Guide Revolt". The New York Times. http://www.nytimes.com/2011/02/10/world/middleeast/10youth.html. 
66. ^ ^{a b} Berdal, S.R.B. (2004) (PDF), Public deliberation on the Web: A Habermasian inquiry into online discourse, Oslo: University of Oslo, http://www.duo.uio.no/publ/informatikk/2004/20535/SimonBerdal.pdf 
67. ^ Kiva Is Not Quite What It Seems, by David Roodman, Center for Global Development, 2 Oct. 2009, as accessed 2 & 16 Jan 2010
68. ^ Confusion on Where Money Lent via Kiva Goes, by Stephanie Strom, in The New York Times, 8 Nov. 2009, as accessed 2 & 16 Jan 2010
69. ^ "Zidisha Set to "Expand" in Peer-to-Peer Microfinance", Microfinance Focus, Feb 2010
70. ^ Access Controlled: The Shaping of Power, Rights, and Rule in Cyberspace, Ronald J. Deibert, John G. Palfrey, Rafal Rohozinski, and Jonathan Zittrain (eds), MIT Press, April 2010, ISBN 0-262-51435-4, ISBN 978-0-262-51435-4
71. ^ "Finland censors anti-censorship site". The Register. 18 February 2008. http://www.theregister.co.uk/2008/02/18/finnish_policy_censor_activist/. Retrieved 19 February 2008. 

External links

Find more about Internet on Wikipedia's sister projects:
	Definitions and translations from Wiktionary
	Images and media from Commons
	Learning resources from Wikiversity
	News stories from Wikinews
	Quotations from Wikiquote
	Source texts from Wikisource
	Textbooks from Wikibooks

	Book: Internet
Wikipedia books are collections of articles that can be downloaded or ordered in print.

Organizations

• The Internet Society
• Berkman Center for Internet and Society
• European Commission Information Society
• Living Internet, Internet history and related information, including information from many creators of the Internet

Articles, books, and journals

• First Monday, a peer-reviewed journal on the Internet established in 1996 as a Great Cities Initiative of the University Library of the University of Illinois at Chicago, ISSN: 1396-0466
• Rise of the Network Society, Manual Castells, Wiley-Blackwell, 1996 (1st ed) and 2009 (2nd ed), ISBN 978-1-4051-9686-4
• "The Internet: Changing the Way We Communicate" in America's Investment in the Future, National Science Foundation, Arlington, Va. USA, 2000
• “Lessons from the History of the Internet”, Manuel Castells, in The Internet Galaxy, Ch. 1, pp 9–35, Oxford University Press, 2001, ISBN 978-0-19-925577-1 ISBN10: 0-19-925577-6
• "Media Freedom Internet Cookbook" by the OSCE Representative on Freedom of the Media Vienna, 2004
• "How Much Does The Internet Weigh?", by Stephen Cass, Discover, 2007
• "Mapping a medusa: The Internet spreads its tentacles", Julie Rehmeyer, Science News, Vol. 171, No. 25, pp. 387–388, 23 June 2007
• Internet, Lorenzo Cantoni & Stefano Tardini, Routledge, 2006, ISBN 978-0-203-69888-4
• The Internet Explained, Vincent Zegna & Mike Pepper, Sonet Digital, November 2005, Pages 1 - 7.

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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