World Wide Web

The World Wide Web ("WWW" or simply the "Web") is a global, read-write information space. Text documents, images, multimedia and many other items of information, referred to as resources, are identified by short, unique, global identifiers called Uniform Resource Identifiers (URIs) so that each can be found, accessed and cross-referenced in the simplest possible way.
The term is often mistakenly used as a synonym for the Internet itself, but the Web is actually something that is available via the Internet, just like e-mail and many other Internet services.
==Basic terms==
The World Wide Web is the combination of 4 basic ideas:
*Hypertext: a format of information which allows one, in a computer environment, to move from one part of a document to another or from one document to another through internal connections among these documents (called "Hyperlinks");
*Resource Identifiers: unique identifiers used to locate a particular resource (computer file, document or other resource) on the network;
*The client-server model of computing: a system in which client software or a client computer makes requests of server software or a server computer that provides the client with resources or services, such as data or files; and
*Markup Language: characters or codes embedded in text which indicate structure, semantic meaning, or advice on presentation.
On the World Wide Web, a client program called a web browser retrieves information resources, such as web pages and other computer files, from web servers using their URLs and displays them, typically on a computer monitor. The most popular web browser is Microsoft's Internet Explorer, followed by Mozilla's Firefox. The most popular browser on the Macintosh is Safari. One can then follow hyperlinks in each page to other resources on the World Wide Web whose location is provided by these hyperlinks. It is also possible, for example by filling in and submitting web forms, to post information back to a web server for it to save or process in some way. The act of following hyperlinks is often called "browsing" or "surfing" the Web. Web pages are often arranged in collections of related material called "Websites."
The phrase "surfing the Internet" was first popularized in print by Jean Armour Polly, a librarian, in an article called Surfing the INTERNET, published in the University of Minnesota's Wilson Library Bulletin in June, 1992. Although Polly may have developed the phrase independently, slightly earlier uses of similar terms have been found on the Usenet from 1991 and 1992, and some recollections claim it was also used verbally in the hacker community for a couple years before that. Polly is famous as NetMom in the history of the Internet.
==How the Web works ==
When a viewer wants to access a web page or other resource on the World Wide Web, he normally begins either by typing the URL of the page into his or her web browser, or by following a Hypertext link to that page or resource. The first step, behind the scenes, is for the server-name part of the URL to be resolved into an IP Address by the global, distributed Internet database known as the Domain Name System (DNS).
The next step is for an HTTP request to be sent to the web server at that IP address, for the page required. In the case of a typical web page, the HTML text, graphics and any other files that form a part of the page will be requested and returned to the client (the web browser) in quick succession.
The web browser's job is then to render the page as described by the HTML, CSS and other files received, incorporating the images, links and other resources as necessary. This produces the on-screen 'page' that the viewer sees.
Most web pages will themselves contain hyperlinks to other relevant and informative pages and perhaps to downloads, source documents, definitions and other web resources.
Such a collection of useful, related resources, interconnected via hypertext links, is what has been dubbed a 'web' of information. Making it available on the Internet produced what Tim Berners-Lee first called the World Wide Web in the early 1990s .
==Origins==
The underlying ideas of the Web can be traced as far back as 1980, when Tim Berners-Lee built ENQUIRE (referring to Enquire Within Upon Everything, a book he recalled from his youth). While it was rather different from the Web we use today, it contained many of the same core ideas (and even some of the ideas of Berners-Lee's next project after the WWW, the Semantic Web).
In March 1989, Tim Berners-Lee wrote Information Management: A Proposal, which referenced ENQUIRE and described a more elaborate information management system. With help from Robert Cailliau, he published a more formal proposal for the World Wide Web in 1990.
A NeXTcube was used by Berners-Lee as the world's first web server and also to write the first web browser, WorldWideWeb in 1990.
By Christmas 1990, Berners-Lee had built all the tools necessary for a working Web : the WorldWideWeb (which was a Web editor as well), the first Web server and the first Web pages which described the project itself.
On August 6, 1991, he posted a short summary of the World Wide Web project on the alt.hypertext newsgroup. This date also marked the debut of the Web as a publicly available service on the Internet.
The crucial underlying concept of hypertext originated with older projects from the 1960s, such as Ted Nelson's Project Xanadu and Douglas Engelbart's oN-Line System (NLS). Both Nelson and Engelbart were in turn inspired by Vannevar Bush's microfilm-based "memex," which was described in the 1945 essay "As We May Think".
Berners-Lee's breakthrough was to marry hypertext to the Internet. In his book Weaving The Web, he explains that he had repeatedly suggested that a marriage between the two technologies was possible to members of both technical communities, but when no one took up his invitation, he finally tackled the project himself. In the process, he developed a system of globally unique identifiers for resources on the Web and elsewhere: the Uniform Resource Identifier.
The World Wide Web had a number of differences from other hypertext systems that were then available:
*The WWW required only unidirectional links rather than bidirectional ones. This made it possible for someone to link to another resource without action by the owner of that resource. It also significantly reduced the difficulty of implementing Web servers and browsers (in comparison to earlier systems), but in turn presented the chronic problem of broken links.
*Unlike certain applications, such as HyperCard, the World Wide Web was non-proprietary, making it possible to develop servers and clients independently and to add extensions without licensing restrictions.
On April 30, 1993, CERN announced that the World Wide Web would be free to anyone, with no fees due. Coming two months after the announcement that Gopher was no longer free to use, this produced a rapid shift away from gopher and towards the Web.
An early popular web browser was ViolaWWW which was based upon HyperCard. The World Wide Web, however, only gained critical mass with the 1993 release of the graphical Mosaic by the National Center for Supercomputing Applications developed by Marc Andreessen. Prior to the release of Mosaic, graphics were not commonly mixed with text in Web pages and its popularity was less than older protocols in use over the Internet, such as Gopher protocol and Wide area information server. Mosaic's graphical user interface allowed the Web to become by far the most popular Internet protocol.
==Web standards==
At its core, the Web is made up of three standards:
*the Uniform Resource Identifier (URI), also know as URL or Universal Resource Locater, which is a universal system for referencing resources on the Web, such as Web pages;
*the HyperText Transfer Protocol (HTTP), which specifies how the browser and server communicate with each other; and
*the HyperText Markup Language (HTML), used to define the structure and content of hypertext documents.
Sir Tim Berners-Lee now heads the World Wide Web Consortium (W3C), which develops and maintains these and other standards that enable computers on the Web to effectively store and communicate different forms of information.
==Sociological implications==
The Web, as it stands today, has allowed global interpersonal exchange on a scale unprecedented in human history. People separated by vast distances, or even large amounts of time, can use the Web to exchange — or even mutually develop — their most intimate and extensive thoughts, or alternately their most casual attitudes and spirits. Emotional experiences, political ideas, cultural customs, musical idioms, business advice, artwork, photographs, literature, can all be shared and disseminated digitally with less individual investment than ever before in human history. Although the existence and use of the Web relies upon material technology, which comes with its own disadvantages, its information does not use physical resources in the way that libraries or the printing press have. Therefore, propagation of information via the Web (via the Internet, in turn) is not constrained by movement of physical volumes, or by manual or material copying of information. And by virtue of being digital, the information of the Web can be searched more easily and efficiently than any library or physical volume, and vastly more quickly than a person could retrieve information about the world by way of physical travel or by way of mail, telephone, telegraph, or any other communicative medium.
The Web is the most far-reaching and extensive medium of personal exchange to appear on Earth. It has probably allowed many of its users to interact with many more groups of people, dispersed around the planet in time and space, than is possible when limited by physical contact or even when limited by every other existing medium of communication combined.
Because the Web is global in scale, some have suggested that it will nurture mutual understanding on a global scale. By definition or by necessity, the Web has such a massive potential for social exchange, it has the potential to nurture empathy and symbiosis, but it also has the potential to incite belligerence on a global scale, or even to empower demagogues and repressive regimes in ways that were historically impossible to achieve.
==Publishing web pages==
The Web is available to individuals outside mass media. In order to "publish" a web page, one does not have to go through a publisher or other media institution, and potential readers could be found in all corners of the globe.
Unlike books and documents, hypertext does not have a linear order from beginning to end. It is not broken down into the hierarchy of chapters, sections, subsections, etc.
Many different kinds of information are now available on the Web, and for those who wish to know other societies, their cultures and peoples, it has become easier. When travelling in a foreign country or a remote town, one might be able to find some information about the place on the Web, especially if the place is in one of the developed countries. Local newspapers, government publications, and other materials are easier to access, and therefore the variety of information obtainable with the same effort may be said to have increased, for the users of the Internet.
Although some websites are available in multiple languages, many are in the local language only. Also, not all software supports all special characters, and thus do not support all languages equally. These factors would challenge the notion that the World Wide Web will bring a unity to the world.
The increased opportunity to publish materials is certainly observable in the countless personal pages, as well as pages by families, small shops, etc., facilitated by the emergence of free web hosting services.
== Pronunciation of "www" ==
In English, WWW is the longest possible three-letter acronym to pronounce, requiring nine syllables. The late Douglas Adams once quipped,"
The World Wide Web is the only thing I know of whose shortened form takes three times longer to say than what it's short for."
Shorter variants include "triple 'double u'", "triple dub", "dub dub dub", "wuh wuh wuh," and "all the 'double u's". In other languages, "www" is often pronounced as "vvv" or "3w". The early "w³" abbreviation is nowadays depreciated.
==Standards==
The following is a cursory list of the documents that define the World Wide Web's three core standards:
*Uniform Resource Locators (URL)
**RFC 1738, Uniform Resource Locators (URL) (December 1994)
**RFC 3986, Uniform Resource Identifier (URI): Generic Syntax (January 2005)
*HyperText Transfer Protocol (HTTP)
**RFC 1945, HTTP/1.0 specification (May 1996)
**RFC 2616, HTTP/1.1 specification (June 1999)
**RFC 2617, HTTP Authentication
**HTTP/1.1 specification errata
*Hypertext Markup Language (HTML)
**Internet Draft, HTML version 1
**RFC 1866, HTML version 2.0
**HTML 3.2 Reference Specification
**HTML 4.01 Specification
**Extensible HTML (XHTML) Specification
==External links==
*World Wide Web Consortium
*Open Directory — Computers: Internet: Web Design and Development
*WWW-Virtual Library: History of the Internet & W3
*Early archive of the first web site
*Internet Statistics: Growth and Usage of the Web and the Internet
*The History of the Web
*Webology
*The World Wide Web Virtual Library: Web Site Tools from the World Wide Web Virtual Library
*A comprehensive history with people, concepts and many interesting quotations
*no-www: www is deprecated
*The World's First Webserver
*Fast UK Server
*ESDS Servers
==Using content from Wikipedia==
Category:Concepts & Terms