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{{dablink|"The World Wide Web," "WWW" and "Web surfing" redirects here. For the Web browser, see [[WorldWideWeb]]. For other uses, see [[Web]] and [[WWW (disambiguation)]]. }}
[[Image:WWWlogo.png|thumb|120px|WWW's historic logo designed by [[Robert Cailliau]]]]

The '''World Wide Web ''' (commonly abbreviated as "'''the Web'''") is a very large set of interlinked [[hypertext]] documents accessed via the [[Internet]]. With a [[Web browser]], one can view [[Web page]]s that may contain [[writing|text]], [[image]]s, [[video]]s, and other [[multimedia]] and navigate between them using [[hyperlink]]s. Using concepts from earlier hypertext systems, the World Wide Web was begun in 1992 by the English physicist Sir [[Tim Berners-Lee]], now the Director of the [[World Wide Web Consortium]], and [[Robert Cailliau]], a Belgian computer scientist, while both were working at [[CERN]] in [[Geneva]], [[Switzerland]]. In 1990, they proposed building a "web of nodes" storing "hypertext pages" viewed by "browsers" on a network,<ref name=W90/> and released that web in 1992. Connected by the existing Internet, other [[website]]s were created, around the world, adding international standards for [[domain name]]s & the [[HTML]] language. Since then, Berners-Lee has played an active role in guiding the development of Web standards (such as the [[markup language]]s in which Web pages are composed), and in recent years has advocated his vision of a [[Semantic Web]]. Cailliau went on early retirement in January 2005 and left CERN in January 2007.

The World Wide Web enabled the spread of information over the [[Internet]] through an easy-to-use and flexible format. It thus played an important role in popularizing use of the Internet.<ref>[http://legal-dictionary.thefreedictionary.com/Internet Internet] Free-Dictionary.com; Accessed 25-11-08</ref> Although the two terms are sometimes [[conflation|conflated]] in popular use, ''World Wide Web'' is not [[synonym]]ous with ''Internet''.<ref>[http://www.techterms.com/definition/www WWW(World Wide Web)] TechTerms.com; Accessed 25-22-08</ref> The Internet consists of a worldwide collection of computers and sub-networks exchanging data using wires, cables, and radio links, whereas the World Wide Web is a huge set of documents, images, and other 'resources' linked by an abstract 'web' of hypertext links and [[URL]]s.

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

Viewing a [[Web page]] on the World Wide Web normally begins either by typing the [[Uniform Resource Locator|URL]] of the page into a [[Web browser]], or by following a [[hyperlink]] to that page or resource. The Web browser then initiates a series of communication messages, behind the scenes, in order to fetch and display it.

=== Page-by-page model ===

Traditionally, each chunk of information sent by a web server to a browser must be explicitly requested. Each time the user opens a new [[web page]], the browser initiates an [[Hypertext Transfer Protocol|HTTP]] connection to the [[web server]]. The browser requests a page for which the server returns the HTML code and waits for more requests on the same connection. The browser typically makes multiple HTTP requests, for each resource used by the page the server responds with data, e.g. images and [[Cascading Style Sheets|stylesheets]]. For example [[Wikipedia]] is a web application built using this page-by-page web model.

First, the server-name portion of the URL is resolved into an [[IP address]] using the global, distributed [[Internet]] database known as the [[domain name system]], or DNS. This IP address is necessary to contact and send data [[Packet (information technology)|packets]] to the [[Web server]]. The browser then requests the resource by sending an [[Hypertext Transfer Protocol|HTTP]] request to the Web server at that particular address. In the case of a typical Web page, the [[HTML]] text of the page is requested first and [[Parsing|parsed]] immediately by the Web browser, which will then make additional requests for images and any other files that form a part of the page. Statistics measuring a website's popularity are usually based on the number of '[[page view]]s' or associated server '[[Hit (internet)|hits]]', or file requests, which take place.

Having received the required files from the Web server, the browser then [[Layout engine|renders]] the page onto the screen as specified by its HTML, [[Cascading Style Sheets|CSS]], and other Web languages. Any images and other resources are incorporated to produce the on-screen Web page that the user sees.

Most Web pages will themselves contain [[hyperlink]]s to other related 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 was dubbed a "web" of information. Making it available on the Internet created what [[Tim Berners-Lee]] first called the '''WorldWideWeb''' (in its original [[CamelCase]], which was subsequently discarded) in November 1990.<ref name="W90">"[http://www.w3.org/Proposal.html WorldWideWeb: Proposal for a HyperText Project]", Tim Berners-Lee & Robert Cailliau, November 12, 1990.</ref>

=== Ajax polling ===
{{main|Ajax (programming)}}
<!-- TODO: Image of Ajax model -->
To overcome limitations of the page-by-page model, some web applications use [[Ajax (programming)|Ajax]] ([[Asynchronous I/O|asynchronous]] [[JavaScript]] and [[XML]]). With Ajax the browser uses JavaScript to modify the current page rather than creating a new page for each request. This limits the server’s response to only the relevant information. Since multiple Ajax requests can be handled at the same time, users can interact with a page even while data is retrieved. Some web applications regularly [[polling (computer science)|poll]] the server to ask if new information is available. High polling frequencies can waste server resources and bandwidth, however web applications with relatively few users can use polling without significant overhead.

=== Web server push ===
{{main|Push technology}}
[[Netscape]] introduced “server push” technology, where the server would constantly send new data to the client through the initial connection, that remains open. This was made possible by the use of server side programming and by the [[MIME#Multipart messages|multipart feature of the MIME standard]].<ref name="html_xhtml">{{cite book
|last=Kennedy
|first=Bill
|authorlink=Bill Kennedy (computer scientist)
|title=HTML & XHTML the Definitive Guide
|series=The Definitive Guide
|date=2008-10-17
|publisher=[[O'Reilly Media]]
|language=English
|isbn=0596527322
|chapter=13.3 - Server-Push Documents
|page=654
}}</ref>

==History==
{{main|History of the World Wide Web}}
[[Image:Premier serveur Web.jpeg|thumb|This [[NeXT Computer]] used by [[Sir Tim Berners-Lee]] at CERN became the first Web server.]]

The underlying ideas of the Web can be traced as far back as 1980, when, at [[CERN]] in [[Switzerland]], [[Sir Tim Berners-Lee]] built [[ENQUIRE]] (a reference to ''[[Enquire Within Upon Everything]]'', a book he recalled from his youth). While it was rather different from the system in use today, it contained many of the same core ideas (and even some of the ideas of Berners-Lee's next project after the World Wide Web, the [[Semantic Web]]).

In March 1989, Berners-Lee wrote a proposal<ref>''[http://www.w3.org/History/1989/proposal.html Information Management: A Proposal]''</ref> which referenced ENQUIRE and described a more elaborate information management system. With help from [[Robert Cailliau]], he published a more formal proposal (on November 12, 1990) to build a "[[Hypertext]] project" called "WorldWideWeb" (one word, also "W3")<ref name=W90/> as a "web of nodes" with "hypertext documents" to store data. That data would be viewed in "hypertext pages" (webpages) by various "[[Web browser|browser]]s" (line-mode or full-screen) on the computer network, using an "access protocol" connecting the "Internet and [[DECnet]] protocol worlds".<ref name=W90/>

The proposal had been modeled after EBT's (Electronic Book Technology, a spin-off from the Institute for Research in Information and Scholarship at Brown University) [[Dynatext]] [[SGML]] reader that CERN had licensed. The [[Dynatext]] system, although technically advanced (a key player in the extension of SGML ISO 8879:1986 to Hypermedia within [[HyTime]]), was considered too expensive and with an inappropriate licensing policy for general HEP (High Energy Physics) community use: a fee for each document and each time a document was changed.

A [[NeXT Computer]] 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:<ref>[http://www.w3.org/People/Berners-Lee/WorldWideWeb Tim Berners-Lee: WorldWideWeb, the first Web client<!-- Bot generated title -->]</ref> the [[WorldWideWeb|first Web browser]] (which was a Web editor as well), the first Web server, and the first Web pages<ref>[http://www.w3.org/History/19921103-hypertext/hypertext/WWW/TheProject.html First Web pages]</ref> which described the project itself.

On August 6, 1991, he posted a short summary of the World Wide Web project on the <tt>alt.hypertext</tt> [[newsgroup]].<ref>[http://groups.google.com/group/alt.hypertext/msg/395f282a67a1916c Short summary of the World Wide Web project]</ref> This date also marked the debut of the Web as a publicly available service on the Internet.

The first server outside Europe was set up at [[SLAC]] in December 1991.<ref>[http://www.slac.stanford.edu/history/earlyweb/history.shtml The Early World Wide Web at SLAC: Early Chronology and Documents<!-- Bot generated title -->]</ref>

The crucial underlying concept of [[hypertext]] originated with older projects from the 1960s, such as the Hypertext Editing System (HES) at Brown University--- among others [[Ted Nelson]] and [[Andries van Dam]]--- [[Ted Nelson]]'s [[Project Xanadu]] and [[Douglas Engelbart]]'s [[NLS (computer system)|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 Web 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 [[link rot]]. Unlike predecessors 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<ref>[http://tenyears-www.web.cern.ch/tenyears-www/Welcome.html Ten Years Public Domain for the Original Web Software]</ref> that the World Wide Web would be free to anyone, with no fees due. Coming two months after the announcement that the [[Gopher (protocol)]] protocol 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]].

[[Mosaic (web browser)#Importance of Mosaic|Scholars generally agree]] that a turning point for the World Wide Web began with the introduction<ref>[http://www.livinginternet.com/w/wi_mosaic.htm Mosaic Web Browser History - NCSA, Marc Andreessen, Eric Bina<!-- Bot generated title -->]</ref> of the [[Mosaic (web browser)|Mosaic]] Web browser<ref>[http://www.totic.org/nscp/demodoc/demo.html NCSA Mosaic - September 10, 1993 Demo<!-- Bot generated title -->]</ref> in 1993, a graphical browser developed by a team at the [[National Center for Supercomputing Applications]] at the [[University of Illinois at Urbana-Champaign]] (NCSA-UIUC), led by [[Marc Andreessen]]. Funding for Mosaic came from the U.S. ''High-Performance Computing and Communications Initiative'', a funding program initiated by the ''[[High Performance Computing and Communication Act of 1991]]'', one of [[Al Gore and information technology|several computing developments]] initiated by U.S. Senator [[Al Gore]].<ref>[http://www.cs.washington.edu/homes/lazowska/faculty.lecture/innovation/gore.html Vice President Al Gore's ENIAC Anniversary Speech<!-- Bot generated title -->]</ref> 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)|Gopher]] and [[Wide Area Information Servers]] (WAIS). Mosaic's graphical user interface allowed the Web to become, by far, the most popular Internet protocol.

The World Wide Web Consortium (W3C) was founded by Tim Berners-Lee after he left the European Organization for Nuclear Research ([[CERN]]) in October, 1994. It was founded at the [[Massachusetts Institute of Technology]] Laboratory for Computer Science (MIT/LCS) with support from the [[Defense Advanced Research Projects Agency]] (DARPA)—which had pioneered the [[Internet]]—and the [[European Commission]].

==Standards==
{{Main|Web standards}}
Many formal standards and other technical specifications define the operation of different aspects of the World Wide Web, the Internet, and computer information exchange. Many of the documents are the work of the [[World Wide Web Consortium]] (W3C), headed by Berners-Lee, but some are produced by the [[Internet Engineering Task Force]] (IETF) and other organizations.

Usually, when Web standards are discussed, the following publications are seen as foundational:
*Recommendations for [[markup languages]], especially [[HTML]] and [[XHTML]], from the W3C. These define the structure and interpretation of [[hypertext]] documents.
*Recommendations for [[style sheet (web development)|stylesheets]], especially [[Cascading Style Sheets|CSS]], from the W3C.
*Standards for [[ECMAScript]] (usually in the form of [[JavaScript]]), from [[Ecma International]].
*Recommendations for the [[Document Object Model]], from W3C.

Additional publications provide definitions of other essential technologies for the World Wide Web, including, but not limited to, the following:
*''Uniform Resource Identifier'' ([[Uniform Resource Identifier|URI]]), which is a universal system for referencing resources on the Internet, such as hypertext documents and images. URIs, often called URLs, are defined by the IETF's RFC 3986 / STD 66: ''Uniform Resource Identifier (URI): Generic Syntax'', as well as its predecessors and numerous [[URI scheme]]-defining [[Request For Comments|RFCs]];
*''HyperText Transfer Protocol (HTTP)'', especially as defined by RFC 2616: ''HTTP/1.1'' and RFC 2617: ''HTTP Authentication'', which specify how the browser and server authenticate each other.

==Privacy==

Computer users, who save time and money, and who gain conveniences and entertainment, may or may not have surrendered the right to [[privacy]] in exchange for using a number of technologies including the Web.<ref name=Bits>{{cite book|author=Hal Abelson, Ken Ledeen and Harry Lewis|title=Blown to Bits: Your Life, Liberty, and Happiness After the Digital Explosion |url=http://www.bitsbook.com/|date=April 14, 2008|isbn=0-13-713559-9|chapter=1–2|publisher=Addison Wesley|accessdate=2008-11-06}}</ref> Worldwide, more than a half billion people have used a [[social network service]],<ref>{{cite press release|title=Social Networking Explodes Worldwide as Sites Increase their Focus on Cultural Relevance|url=http://www.comscore.com/press/release.asp?press=2396|publisher=comScore|date=August 12, 2008|accessdate=2008-11-09}}</ref> and of Americans who grew up with the Web, half created an online profile<ref>{{cite web|author=Amanda Lenhart and Mary Madden|title=Teens, Privacy & Online Social Networks|url=http://www.pewinternet.org/pdfs/PIP_Teens_Privacy_SNS_Report_Final.pdf|date=April 18, 2007|format=PDF|publisher=Pew Internet & American Life Project|accessdate=2008-11-09}}</ref> and are part of a generational shift that could be changing norms.<ref>{{cite video|people=Schmidt, Eric (Google)|date2=2008-10-20|title=Eric Schmidt at Bloomberg on the Future of Technology|url=http://www.youtube.com/watch?v=rD_x9LW5QRg|publisher=YouTube|location=New York, New York|accessdate=2008-11-09|time=16:30}}</ref><ref>U.S. youth in {{cite news|author=Nussbaum, Emily|title=Say Everything|url=http://nymag.com/news/features/27341/|date=February 12, 2007|work=New York|publisher=New York Media|accessdate=2008-11-09}}</ref> Among services paid for by advertising, [[Yahoo!]] could collect the most data about users of commercial websites, about 2,500 bits of information per month about each typical user of its site and its affiliated [[advertising network]] sites. Yahoo! was followed by [[MySpace]] with about half that potential and then by [[AOL]]-[[TimeWarner]], [[Google]], [[Facebook]], [[Microsoft]], and [[eBay]].<ref>{{cite news|author=Story, Louise and comScore|title=They Know More Than You Think|url=http://www.nytimes.com/imagepages/2008/03/10/technology/20080310_PRIVACY_GRAPHIC.html|format=JPEG|date=[[March 10]], [[2008]]}} in {{cite news|author=Story, Louise|title=To Aim Ads, Web Is Keeping Closer Eye on You|url=http://www.nytimes.com/2008/03/10/technology/10privacy.html|work=The New York Times|publisher=The New York Times Company|date=[[March 10]], [[2008]]|accessdate=2008-03-09}}</ref>

Privacy representatives from 60 countries have resolved to ask for laws to complement industry self-regulation, for education for children and other minors who use the Web, and for default protections for users of social networks.<ref name=conference>{{cite press release|title=Protecting privacy in a borderless world|url=http://www.privacyconference2008.org/pdf/press_final_en.pdf|format=PDF|date=October 17, 2008|title=30th International Conference of Data Protection and Privacy Commissioners|accessdate=2008-11-08}}</ref> They also believe data protection for [[personally identifiable information]] benefits business more than the sale of that information.<ref name=conference /> Users can opt-in to features in browsers to clear their personal histories locally and block some [[HTTP cookie|cookies]] and advertising networks<ref>{{cite web|author=Cooper, Alissa|title=Browser Privacy Features: A Work In Progress|url=http://www.cdt.org/privacy/20081022_browser_priv.pdf|format=PDF|publisher=Center for Democracy and Technology|date=October 2008|accessdate=2008-11-08}}</ref> but they are still tracked in websites' [[server log]]s, and particularly [[Web beacons]].{{fact|date=November 2008}} Berners-Lee and colleagues see hope in accountability and appropriate use achieved by extending the Web's architecture to policy awareness, perhaps with audit logging, reasoners and appliances.<ref name=Weitzner>{{cite web|author=Daniel J. Weitzner, Harold Abelson, Tim Berners-Lee, Joan Feigenbaum, James Hendler, Gerald Jay Sussman|title=Information Accountability|url=http://hdl.handle.net/1721.1/37600|date=June 13, 2007|publisher=MIT Computer Science and Artificial Intelligence Laboratory|accessdate=2008-11-06}}</ref>

==Security==
The Web has become criminals' preferred pathway for spreading [[malware]]. Cybercrime carried out on the Web can include [[identity theft]], fraud, espionage and intelligence gathering.<ref name=Ben-Itzhak /> Web-based vulnerabilities now outnumber traditional computer security concerns,<ref>XSS vulnerabilties outnumbered buffer overflows, in {{cite web|author=Christey, Steve and Martin, Robert A.|title=Vulnerability Type Distributions in CVE (version 1.1)|url=http://cwe.mitre.org/documents/vuln-trends/index.html|date=[[May 22]], [[2007]]|publisher=MITRE Corporation|accessdate=2008-06-07}} During the second half of 2007, XSS outnumbered "traditional" vulnerabilities, in {{cite web|title=Symantec Internet Security Threat Report: Trends for July-December 2007 (Executive Summary)|publisher=Symantec Corp.|volume=XIII|pages=1–2|date=April 2008|url=http://eval.symantec.com/mktginfo/enterprise/white_papers/b-whitepaper_exec_summary_internet_security_threat_report_xiii_04-2008.en-us.pdf|format=PDF|accessdate=2008-05-11}}</ref> and as measured by [[Google]], about one in ten Web pages may contain malicious code.<ref>{{cite news|title=Google searches web's dark side|url=http://news.bbc.co.uk/2/hi/technology/6645895.stm|date=[[May 11]], [[2007]]|publisher=BBC News|accessdate=2008-04-26}}</ref> Most Web-based attacks take place on legitimate websites, and most, as measured by [[Sophos]], are hosted in the United States, China and Russia.<ref name=Sophos-Q1-2008>{{cite web|title=Security Threat Report|url=http://www.sophos.com/sophos/docs/eng/marketing_material/sophos-threat-report-Q108.pdf|format=PDF|date=Q1 2008|publisher=Sophos|accessdate=2008-04-24}}</ref>

The most common of all malware threats is [[SQL injection]] attacks against websites.<ref>{{cite web|title=Security threat report|url=http://www.sophos.com/sophos/docs/eng/papers/sophos-security-report-jul08-srna.pdf|format=PDF|date=July 2008|publisher=Sophos|accessdate=2008-08-24}}</ref> Through HTML and URIs the Web was vulnerable to attacks like [[cross-site scripting]] (XSS) that came with the introduction of JavaScript<ref name=FGHR>{{cite book|author=Fogie, Seth, Jeremiah Grossman, Robert Hansen, and Anton Rager|title=Cross Site Scripting Attacks: XSS Exploits and Defense|pages=68–69, 127|publisher=Syngress, Elsevier Science & Technology|url=http://www.syngress.com/book_catalog//SAMPLE_1597491543.pdf|format=PDF|date=2007|isbn=1597491543|accessdate=2008-06-06}}</ref> and were exacerbated to some degree by Web 2.0 and Ajax [[web design]] that favors the use of scripts.<ref>{{cite web|author=O'Reilly, Tim|title=What Is Web 2.0|url=http://www.oreillynet.com/pub/a/oreilly/tim/news/2005/09/30/what-is-web-20.html|pages=4–5|date=[[September 30]], [[2005]]|publisher=O'Reilly Media|accessdate=2008-06-04}} and AJAX web applications can introduce security vulnerabilities like "client-side security controls, increased attack surfaces, and new possibilities for Cross-Site Scripting (XSS)", in {{cite journal|author=Ritchie, Paul|title=The security risks of AJAX/web 2.0 applications|url=http://www.infosecurity-magazine.com/research/Sep07_Ajax.pdf|format=PDF|date=March 2007|journal=Infosecurity|publisher=Elsevier|accessdate=2008-06-06}} which cites {{cite news|author=Hayre, Jaswinder S. and Kelath, Jayasankar|title=Ajax Security Basics|url=http://www.securityfocus.com/infocus/1868|publisher=SecurityFocus|date=[[June 22]], [[2006]]|accessdate=2008-06-06}}</ref> Today by one estimate, 70% of all websites are open to XSS attacks on their users.<ref>{{cite news|author=Berinato, Scott|title=Software Vulnerability Disclosure: The Chilling Effect|url=http://www.csoonline.com/article/221113|work=CSO|page=7|publisher=CXO Media|date=[[January 1]], [[2007]]|accessdate=2008-06-07}}</ref>

Proposed solutions vary to extremes. Large security vendors like [[McAfee]] already design governance and compliance suites to meet post-9/11 regulations,<ref>{{cite news|author=Prince, Brian|title=McAfee Governance, Risk and Compliance Business Unit|url=http://www.eweek.com/c/a/Security/McAfee-Governance-Risk-and-Compliance-Business-Unit/|work=eWEEK|publisher=Ziff Davis Enterprise Holdings|date=[[April 9]], [[2008]]|accessdate=2008-04-25}}</ref> and some, like [[Finjan]] have recommended active real-time inspection of code and all content regardless of its source.<ref name=Ben-Itzhak>{{cite news|author=Ben-Itzhak, Yuval|title=Infosecurity 2008 - New defence strategy in battle against e-crime|url=http://www.computerweekly.com/Articles/2008/04/18/230345/infosecurity-2008-new-defence-strategy-in-battle-against.htm|work=ComputerWeekly|publisher=Reed Business Information|date=[[April 18]], [[2008]]|accessdate=2008-04-20}}</ref> Some have argued that for enterprise to see security as a business opportunity rather than a cost center,<ref>{{cite news|author=Preston, Rob|title=Down To Business: It's Past Time To Elevate The Infosec Conversation|url=http://www.informationweek.com/news/security/client/showArticle.jhtml?articleID=207100989|work=InformationWeek|publisher=United Business Media|date=[[April 12]], [[2008]]|accessdate=2008-04-25}}</ref> "ubiquitous, always-on digital rights management" enforced in the infrastructure by a handful of organizations must replace the hundreds of companies that today secure data and networks.<ref>{{cite news|author=Claburn, Thomas|title=RSA's Coviello Predicts Security Consolidation|url=http://www.informationweek.com/news/security/showArticle.jhtml?articleID=197003826|work=InformationWeek|publisher=United Business Media|date=[[February 6]], [[2007]]|accessdate=2008-04-25}}</ref> [[Jonathan Zittrain]] has said users sharing responsibility for computing safety is far preferable to locking down the Internet.<ref>{{cite news|first=Carolyn|last= Duffy Marsan|title= How the iPhone is killing the 'Net|url= http://www.networkworld.com/news/2008/040908-zittrain.html|work= Network World|publisher= IDG|date= [[April 9]], [[2008]]|accessdate= 2008-04-17}}</ref>

In terms of security as it relates to the 'physical' portion of the World Wide Web/Internet, the 'distributed' nature of the Internet provides security against attack -- as there is no one single 'focus point' through which all Internet traffic is directed, any attempt to 'cripple' the Internet would only disable a small portion of the whole, and the connecting computers would simply direct the affected traffic through other, unaffected networks and computers.

==Web accessibility==
{{Main|Web accessibility}}

Many countries regulate [[web accessibility]] as a requirement for web sites.

==Java==
A significant advance in Web technology was [[Sun Microsystems|Sun Microsystems']] [[Java platform]]. It enables Web pages to embed small programs (called [[applet]]s) directly into the view. These applets run on the end-user's computer, providing a richer user interface than simple Web pages. Java client-side applets never gained the popularity that Sun had hoped for a variety of reasons, including lack of integration with other content (applets were confined to small boxes within the rendered page) and the fact that many computers at the time were supplied to end users without a suitably installed [[Java Virtual Machine]], and so required a download by the user before applets would appear. [[Adobe Flash]] now performs many of the functions that were originally envisioned for Java applets, including the playing of video content, animation, and some rich [[Graphical user interface|GUI]] features. [[Java (programming language)|Java]] itself has become more widely used as a platform and language for [[server-side]] and other programming.

==JavaScript==
[[JavaScript]], on the other hand, is a [[Scripting programming language|scripting language]] that was initially developed for use within Web pages. The standardized version is [[ECMAScript]]. While its name is similar to Java, JavaScript was developed by [[Netscape Communications Corporation|Netscape]] and has very little to do with Java, although the syntax of both languages is derived from the [[C (programming language)|C]] programming language. In conjunction with a Web page's [[Document Object Model]] (DOM), JavaScript has become a much more powerful technology than its creators originally envisioned.{{Fact|date=August 2008}} The manipulation of a page's DOM after the page is delivered to the client has been called [[Dynamic HTML]] (DHTML), to emphasize a shift away from ''static'' HTML displays.

In simple cases, all the optional information and actions available on a JavaScript-enhanced Web page will have been downloaded when the page was first delivered. [[Ajax (programming)|Ajax]] ("Asynchronous JavaScript and XML") is a group of interrelated web development techniques used for creating interactive web applications that provide a method whereby parts ''within'' a Web page may be updated, using new information obtained over the network at a later time in response to user actions. This allows the page to be more responsive, interactive and interesting, without the user having to wait for whole-page reloads. Ajax is seen as an important aspect of what is being called [[Web 2.0]]. Examples of Ajax techniques currently in use can be seen in [[Gmail]], [[Google Maps]], and other dynamic Web applications.

==Publishing Web pages==
Web page production is available to individuals outside the [[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.

Many different kinds of information are available on the Web, and for those who wish to know other societies, cultures, and peoples, it has become easier.

The increased opportunity to publish materials is observable in the countless personal and social networking pages, as well as sites by families, small shops, etc., facilitated by the emergence of free [[Web hosting]] services.

==Statistics==
According to a 2001 study, there were massively more than 550 billion documents on the Web, mostly in the invisible Web, or [[deep Web]].<ref>[http://www.brightplanet.com/resources/details/deepweb.html The 'Deep' Web: Surfacing Hidden Value]</ref> A 2002 survey of 2,024 million Web pages<ref>[http://www.netz-tipp.de/languages.html Distribution of languages on the Internet<!-- Bot generated title -->]</ref> determined that by far the most Web content was in English: 56.4%; next were pages in German (7.7%), French (5.6%), and Japanese (4.9%). A more recent study, which used Web searches in 75 different languages to sample the Web, determined that there were over 11.5 billion Web pages in the [[Surface Web|publicly indexable Web]] as of the end of January 2005.<ref>[http://www.cs.uiowa.edu/~asignori/web-size/ Indexable Web Size<!-- Bot generated title -->]</ref> {{As of|2009|3}}, the indexable web contains at least 25.21 billion pages.<ref>[http://www.worldwidewebsize.com/ The size of the World Wide Web]</ref> On July 25, 2008, Google software engineers Jesse Alpert and Nissan Hajaj announced that [[Google Search]] had discovered one trillion unique URLs.<ref>{{cite web |url=http://googleblog.blogspot.com/2008/07/we-knew-web-was-big.html |title=We knew the web was big... |accessdate= |last=Alpert |first=Jesse |coauthors=Hajaj, Nissan |date=2008-07-25 |work=The Official Google Blog |publisher=}}</ref>

Over 100.1 million websites operated as of March 2008.<ref name=NI>{{cite web|title=Domain Counts & Internet Statistics|url=http://www.domaintools.com/internet-statistics/|publisher=Name Intelligence|accessdate=2008-03-11}}</ref> Of these 74% were commercial or other sites operating in the <code>.com</code> [[generic top-level domain]].<ref name=NI />

==Speed issues==
Frustration over [[congestion]] issues in the [[Internet]] infrastructure and the high [[Latency (engineering)|latency]] that results in slow browsing has led to an alternative, pejorative name for the World Wide Web: the ''World Wide Wait''.{{Fact|date=August 2008}} Speeding up the Internet is an ongoing discussion over the use of [[peering]] and [[Quality of service|QoS]] technologies. Other solutions to reduce the World Wide Wait can be found on [http://www.w3.org/Protocols/NL-PerfNote.html W3C].

Standard [[guideline]]s for ideal Web response times are:<ref>Nielsen 1999, `Designing Web Usability', page 42</ref>
*0.1 second (one tenth of a second). Ideal response time. The user doesn't sense any interruption.
*1 second. Highest acceptable response time. Download times above 1 second interrupt the user experience.
*10 seconds. Unacceptable response time. The user experience is interrupted and the user is likely to leave the site or system.
These numbers are useful for planning server capacity.

==Caching==
If a user revisits a Web page after only a short interval, the page data may not need to be re-obtained from the source Web server. Almost all Web browsers [[cache]] recently-obtained data, usually on the local hard drive. HTTP requests sent by a browser will usually only ask for data that has changed since the last download. If the locally-cached data are still current, it will be reused.

Caching helps reduce the amount of Web traffic on the Internet. The decision about expiration is made independently for each downloaded file, whether image, [[Cascading Style Sheets|stylesheet]], [[JavaScript]], HTML, or whatever other content the site may provide. Thus even on sites with highly dynamic content, many of the basic resources only need to be refreshed occasionally. Web site designers find it worthwhile to collate resources such as CSS data and JavaScript into a few site-wide files so that they can be cached efficiently. This helps reduce page download times and lowers demands on the Web server.

There are other components of the Internet that can cache Web content. Corporate and academic [[Firewall (networking)|firewalls]] often cache Web resources requested by one user for the benefit of all. (See also [[Web proxy#Caching proxy server|Caching proxy server]].) Some [[search engines]], such as [[Google]] or [[Yahoo!]], also store cached content from websites.

Apart from the facilities built into Web servers that can determine when files have been updated and so need to be re-sent, designers of dynamically-generated Web pages can control the HTTP headers sent back to requesting users, so that transient or sensitive pages are not cached. [[Online banking|Internet banking]] and news sites frequently use this facility.

Data requested with an [[Hypertext Transfer Protocol|HTTP]] 'GET' is likely to be cached if other conditions are met; data obtained in response to a 'POST' is assumed to depend on the data that was POSTed and so is not cached.

==Link rot and Web archival==
{{main|Link rot}}
Over time, many Web resources pointed to by hyperlinks disappear, relocate, or are replaced with different content. This phenomenon is referred to in some circles as "[[link rot]]" and the hyperlinks affected by it are often called "[[dead link]]s".

The ephemeral nature of the Web has prompted many efforts to archive Web sites. The [[Internet Archive]] is one of the most well-known efforts; it has been active since 1996.

==Academic conferences==
The major academic event covering the Web is the [[World Wide Web Conference]], promoted by [[IW3C2]].

==WWW prefix in Web addresses==
The letters "www" are commonly found at the beginning of [[Web address]]es because of the long-standing practice of naming Internet hosts (servers) according to the services they provide. So for example, the host name for a [[Web server]] is often "www"; for an [[FTP server]], "ftp"; and for a [[USENET]] [[news server]], "news" or "nntp" (after the news protocol [[NNTP]]). These host names appear as [[Domain name system|DNS]] [[subdomain]] names, as in "www.example.com".

This use of such prefixes is not required by any technical standard; indeed, the first Web server was at "nxoc01.cern.ch",<ref>[http://www.w3.org/People/Berners-Lee/FAQ.html Frequently asked questions by the Press - Tim Berners-Lee<!-- Bot generated title -->]</ref> and even today many Web sites exist without a "www" prefix. The "www" prefix has no meaning in the way the main Web site is shown. The "www" prefix is simply one choice for a Web site's host name.

However, some website addresses require the www. prefix, and if typed without one, won't work; there are also some which must be typed ''without'' the prefix. Sites that do not have Host Headers properly setup are the cause of this. Some hosting companies do not set up a www or @ A record in the web server configuration and/or at the DNS server level.

Some Web browsers will automatically try adding "www." to the beginning, and possibly ".com" to the end, of typed URLs if no host is found without them. All major web browsers will also prefix "<nowiki>http://www.</nowiki>" and append ".com" to the address bar contents if the Control and Enter keys are pressed simultaneously. For example, entering "example" in the address bar and then pressing either Enter or Control+Enter will usually resolve to "<nowiki>http://www.example.com</nowiki>", depending on the exact browser version and its settings.

===Pronunciation of "www"===
{{main|Pronunciation of "www"}}
In [[English language|English]], "www" is pronounced '''"double-u double-u double-u"'''.
The English writer [[Douglas Adams]] once quipped:
{{Quotation|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.|Douglas Adams|[[The Independent|The Independent on Sunday]], 1999}}

It is also interesting that in Mandarin [[Chinese language|Chinese]], "World Wide Web" is commonly translated via a [[phono-semantic matching]] to ''wàn wéi wǎng'' ({{lang|zh|[[wikt:万维网|万维网]]}}), which satisfies "www" and literally means "myriad dimensional net",<ref>See [[CEDICT]] or the [http://www.mdbg.net/chindict/chindict.php?page=translate&trst=0&trqs=World+Wide+Web&trlang=&wddmtm=0 MDBG Chinese-English Dictionary].</ref> a translation that very appropriately reflects the design concept and proliferation of the World Wide Web.

Tim Berners-Lee's web-space states that 'World Wide Web' is officially spelled as three separate words, each capitalized, with no intervening hyphens.<ref>http://www.w3.org/People/Berners-Lee/FAQ.html</ref> Additionally, 'Web' (with a capital 'W') is used to indicate its status as an abbreviation.

== See also ==
<div style="-moz-column-count:3; -webkit-column-count:3; column-count:3;">
*[[Amaya (web browser)|Amaya Web browser]]
*[[Deep web]]
*[[List of websites]]
*[[Web search engine|Search engine]]
*[[Streaming media]]
*[[Web 1.0]]
*[[Web 2.0]]
*[[Web accessibility]]
*[[Web archiving]]
*[[Web directory]]
*[[Web operating system]]
*[[Web science]]
*[[Web services]]
*[[Webology]]
*[[Website architecture]]
</div>

==Notes==
{{reflist|2}}

==References==
*{{cite paper | author=Fielding, R.; Gettys, J.; Mogul, J.; Frystyk, H.; Masinter, L.; Leach, P.; Berners-Lee, T. | title=Hypertext Transfer Protocol — http://1.1 | publisher=Information Sciences Institute | date=June 1999 | version=Request For Comments 2616 | url=ftp://ftp.isi.edu/in-notes/rfc2616.txt}}
*{{cite paper | author=Berners-Lee, Tim; Bray, Tim; Connolly, Dan; Cotton, Paul; Fielding, Roy; Jeckle, Mario; Lilley, Chris; Mendelsohn, Noah; Orchard, David; Walsh, Norman; Williams, Stuart | title=Architecture of the World Wide Web, Volume One | publisher=W3C | date=December 15, 2004 | version=Version 20041215 | url=http://www.w3.org/TR/webarch/}}
*{{cite web | author=Polo, Luciano | title=World Wide Web Technology Architecture: A Conceptual Analysis | publisher= | year=2003 | work=New Devices | url=http://newdevices.com/publicaciones/www/ | dateformat=mdy | accessdate=July 31 2005 }}

==External links==
{{wikibooks|Nets, Webs and the Information Infrastructure}}
{{Portal|Internet|Crystal_Clear_app_browser.png}}


*[http://computemagazine.com/man-who-invented-world-wide-web-gives-new-definition Man Who Invented the World Wide Web Gives it New Definition]
*[http://www.w3.org/History/19921103-hypertext/hypertext/WWW/ Early archive of the first Web site]
*[http://www.mit.edu/people/mkgray/net/ Internet Statistics: Growth and Usage of the Web and the Internet]
*[http://www.livinginternet.com/w/w.htm Living Internet] A comprehensive history of the Internet, including the World Wide Web.
*[http://www2007.org/ Official WWW conference, 2007]
*[http://www2006.org/ Official WWW conference, 2006]
*[http://www.confsearch.org/confsearch/faces/pages/topic.jsp?topic=WWW&sortMode=1&graphicView=1 List of academic conferences covering the World Wide Web] at [http://www.confsearch.org confsearch]
*{{dmoz|Computers/Internet/Web_Design_and_Development|Web Design and Development}}
* [http://www.semantic-systems-biology.org Semantic Systems Biology]
*[http://www.tomandmaria.com/tom/Writing/ProtocolsForProfitDRAFT.pdf Thomas Haigh, "Protocols for Profit: Web and Email Technologies as Product and Infrastructure" in The Internet & American Business, eds. Ceruzzi & Aspray, MIT Press, 2008] Business & technological history of Web browsers, online preprint.
*[http://www.informationweek.com/news/internet/showArticle.jhtml?articleID=199203958 What's The Greatest Web Software Ever Written?]
*[http://www.w3.org/ World Wide Web Consortium]
*[http://www.worldwidewebsize.com/ World Wide Web Size] Daily estimated size of the World Wide Web.
*[http://www.w3c-at.de/wspolicy-pressrelease.php WsPolicy Pressrealease] (German)
*[http://hydrogen.informatik.tu-cottbus.de/wiki/index.php/ Web Technologies Wiki]
*[http://no-www.org/ www. is deprecated.]

[[Category:World Wide Web| ]]
[[Category:English inventions]]
[[Category:Hypertext]]
[[Category:Internet history]]

[[Category:Information Age]]
[[Category:Whole Earth]]
[[Category:1992 introductions]]

{{Link FA|ur}}

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Revision as of 08:21, 30 March 2009

hellllllooooo

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