The "invisible web" is the part of the web that search engines do not have direct access to. It is a vast amount of databases estimated to be 500 times bigger than the visible web that is accessible to search engines.
The 'Deep' web is the part of the web that is not normally accessable to search engines, this is content that is restricted to subscription-only services. The services are normally academic in nature. A web site will allow a web crawler or spiderbot to access specific part of the website, such as the home page, about us pages and contact pages. However academic papers and other content is either on a pay per view or just does not need to be indexed by a search engine (such as administration sections of an ecommerce site). It is this content that is described as being 'The Deep web' because very little of it is actually 'seen' by web crawlers.
A file held within the 'root' web directory called a robots.txt file contains information on what a web crawler can actually index to the search engine it is crawling for.
Hope this helps to answer your questoion.
Ref:
The Deep Web:
http://pipl.com/help/deep-web/
Robots.txt:
http://www.robotstxt.org/
Also referred to as the deep Web, the term refers to either Web pages that cannot be indexed by a typical search engine or Web pages that a search engine purposely does not index, rendering the data "invisible" to the general user.
The term web city can refer to many things. Web city could possibly refer to a particular online community that acts in accordance to the same manner of city folk.
food web
The web address of the Invisible Museum is: invisiblemuseum.org
invisible web or deep web
This could refer to the plus sign (+) which is not shown before the first term in an expression. For example, "5 -3" is "+5 -3".
Able to connect to or be run on the Web. This is a rather broad term that may refer to an application that outputs HTML for display on the Web or that launches a Web browser to retrieve specific Web pages. It can also refer to an application that must run on a Web server, the output of which could be displayed by a browser or a Java application.
This term means Web development environment. It can refer to any stage of development in regards to web pages, sites, social networks and even internet applications.
There are a few different musical terms that refer to a composed invisible note. Cues are notes that are composed but not played.
to what does the term coed refer
The term "WICD" refers to Web Integration Compound Document, Wireless Interface Connection Daemon, Women in Community Development, Waupaca Industrial Development Corporation.
The term PPC traffic refers to 'Pay-per-click' traffic. This is website traffic that is generated by advertisers paying the publisher to advertise their web pages.
The term hotspot usually refer to web design. I've been using and teaching Photoshop for the last 6 years and have never heard the term hotspot in photoshop.