world wide web www and the web redirect here for other uses of www see www disambiguation for other uses of web see web disambiguation for the first web software see worldwideweb not to be confused with the internet a global map of the web index for countries in 2014 the world wide web www also called the web is an information space where documents and other web resources are identified by uniform resource locators urls interlinked by hypertext links and accessible via the internet the browser was released outside cern in 1991 first to other research institutions starting in january 1991 and to the general public on the internet in august 1991 the world wide web has been central to the development of the information age and is the primary tool billions of people use to interact on the internet in addition to formatted text web pages may contain images video audio and software components that are rendered in the users web browser as coherent pages of multimedia content embedded hyperlinks permit users to navigate between web pages multiple web pages with a common theme a common domain name or both make up a website website content can largely be provided by the publisher or interactively where users contribute content or the content depends upon the users or their actions websites may be mostly informative primarily for entertainment or largely for commercial governmental or nongovernmental organisational purpose history history of the world wide web the next computer used by tim bernerslee at cern the corridor where www was born cern ground floor of building no1 tim bernerslees vision of a global hyperlinked information system became a possibility by the second half of the 1980s with help from his colleague and fellow hypertext enthusiast robert cailliau he published a more formal proposal on 12 november 1990 to build a hypertext project called worldwideweb one word as a web of hypertext documents to be viewed by browsers using a clientserver architecture the cern data centre in 2010 housing some www servers the proposal was modelled after the sgml reader dynatext by electronic book technology a spinoff from the institute for research in information and scholarship at brown university the dynatext system licensed by cern was a key player in the extension of sgml iso 88791986 to hypermedia within hytime but it was considered too expensive and had an inappropriate licensing policy for use in the general high energy physics community namely a fee for each document and each document alteration a next computer was used by bernerslee as the worlds first web server and also to write the first web browser worldwideweb in 1990 by christmas 1990 bernerslee had built all the tools necessary for a working web the first web page may be lost but paul jones of uncchapel hill in north carolina announced in may 2013 that bernerslee gave him what he says is the oldest known web page during a 1991 visit to unc jones stored it on a magnetooptical drive and on his next computer the first server outside europe was installed at the stanford linear accelerator center slac in palo alto california to host the spireshep database accounts differ substantially as to the date of this event the world wide web consortiums timeline says december 1992 bernerslees 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 assumed the project himself in the process he developed three essential technologies a system of globally unique identifiers for resources on the web and elsewhere the universal document identifier udi later known as uniform resource locator url and uniform resource identifier uri the publishing language hypertext markup language html the hypertext transfer protocol http the world wide web had a number of differences from other hypertext systems available at the time the web required only unidirectional links rather than bidirectional ones making 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 nonproprietary making it possible to develop servers and clients independently and to add extensions without licensing restrictions on 30 april 1993 cern announced that the world wide web would be free to anyone with no fees due coming two months after the announcement that the server implementation of the gopher 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 for unix and the x windowing system robert cailliau jeanfranois abramatic and tim bernerslee at the 10th anniversary of the world wide web consortium scholars generally agree that a turning point for the world wide web began with the introduction prior to the release of mosaic graphics were not commonly mixed with text in web pages and the webs popularity was less than older protocols in use over the internet such as gopher and wide area information servers wais mosaics 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 bernerslee 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 mitlcs with support from the defense advanced research projects agency darpa which had pioneered the internet a year later a second site was founded at inria a french national computer research lab with support from the european commission dg infso and in 1996 a third continental site was created in japan at keio university by the end of 1994 the total number of websites was still relatively small but many notable websites were already active that foreshadowed or inspired todays most popular services connected by the internet other websites were created around the world this motivated international standards development for protocols and formatting bernerslee continued to stay involved in guiding the development of web standards such as the markup languages to compose web pages and he advocated his vision of a semantic web the world wide web enabled the spread of information over the internet through an easytouse and flexible format it thus played an important role in popularising use of the internet function the world wide web functions as an application layer protocol that is run on top of figuratively the internet helping to make it more functional the advent of the mosaic web browser helped to make the web much more usable to include the display of images and moving images gifs the terms internet and world wide web are often used without much distinction however the two are not the same the internet is a global system of interconnected computer networks in contrast the world wide web is a global collection of documents and other resources linked by hyperlinks and uris web resources are accessed using http or https which are applicationlevel internet protocols that use the internets transport protocols viewing a web page on the world wide web normally begins either by typing the 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 background communication messages to fetch and display the requested page in the 1990s using a browser to view web pagesand to move from one web page to another through hyperlinkscame to be known as browsing web surfing after channel surfing or navigating the web early studies of this new behaviour investigated user patterns in using web browsers one study for example found five user patterns exploratory surfing window surfing evolved surfing bounded navigation and targeted navigation the following example demonstrates the functioning of a web browser when accessing a page at the url httpwwwexampleorghomehtml the browser resolves the server name of the url wwwexampleorg into an internet protocol address using the globally distributed domain name system dns this lookup returns an ip address such as 20301134 or 2001db82e7334 the browser then requests the resource by sending an http request across the internet to the computer at that address it requests service from a specific tcp port number that is well known for the http service so that the receiving host can distinguish an http request from other network protocols it may be servicing the http protocol normally uses port number 80 the content of the http request can be as simple as two lines of text get homehtml http11 host wwwexampleorg the computer receiving the http request delivers it to web server software listening for requests on port 80 if the web server can fulfil the request it sends an http response back to the browser indicating success http10 200 ok contenttype texthtml charsetutf8 followed by the content of the requested page hypertext markup language html for a basic web page might look like this html head titleexampleorg the world wide webtitle head body pthe world wide web abbreviated as www and commonly known p body html the web browser parses the html and interprets the markup title p for paragraph and such that surrounds the words to format the text on the screen many web pages use html to reference the urls of other resources such as images other embedded media scripts that affect page behaviour and cascading style sheets that affect page layout the browser makes additional http requests to the web server for these other internet media types as it receives their content from the web server the browser progressively renders the page onto the screen as specified by its html and these additional resources linking most web pages contain hyperlinks to other related pages and perhaps to downloadable files source documents definitions and other web resources in the underlying html a hyperlink looks like this a hrefhttpwwwexampleorghomehtmlexampleorg homepagea graphic representation of a minute fraction of the www demonstrating hyperlinks such a collection of useful related resources interconnected via hypertext links is dubbed a web of information publication on the internet created what tim bernerslee first called the worldwideweb in its original camelcase which was subsequently discarded in november 1990 the hyperlink structure of the www is described by the webgraph the nodes of the web graph correspond to the web pages or urls the directed edges between them to the hyperlinks over time many web resources pointed to by hyperlinks disappear relocate or are replaced with different content this makes hyperlinks obsolete a phenomenon referred to in some circles as link rot and the hyperlinks affected by it are often called dead links the ephemeral nature of the web has prompted many efforts to archive web sites the internet archive active since 1996 is the best known of such efforts dynamic updates of web pages ajax programming javascript is a scripting language that was initially developed in 1995 by brendan eich then of netscape for use within web pages www prefix many hostnames used for the world wide web begin with www because of the longstanding practice of naming internet hosts according to the services they provide the hostname of a web server is often www in the same way that it may be ftp for an ftp server and news or nntp for a usenet news server these host names appear as domain name system dns or subdomain names as in wwwexamplecom the use of www is not required by any technical or policy standard and many web sites do not use it the first web server was nxoc01cernch when a user submits an incomplete domain name to a web browser in its address bar input field some web browsers automatically try adding the prefix www to the beginning of it and possibly com org and net at the end depending on what might be missing for example entering microsoft may be transformed to httpwwwmicrosoftcom and openoffice to httpwwwopenofficeorg this feature started appearing in early versions of firefox when it still had the working title firebird in early 2003 from an earlier practice in browsers such as lynx in english www is usually read as doubleu doubleu doubleu as the mobile web grew in popularity services like gmailcom outlookcom myspacecom facebookcom and twittercom are most often mentioned without adding www or indeed com to the domain scheme specifiers the scheme specifiers http and https at the start of a web uri refer to hypertext transfer protocol or http secure respectively they specify the communication protocol to use for the request and response the http protocol is fundamental to the operation of the world wide web and the added encryption layer in https is essential when browsers send or retrieve confidential data such as passwords or banking information web browsers usually automatically prepend http to userentered uris if omitted web security for criminals the web has become a venue to spread malware and engage in a range of cybercrimes including identity theft fraud espionage and intelligence gathering two of the wellknown phishing methods are covert redirect and open redirect proposed solutions vary large security companies like mcafee already design governance and compliance suites to meet post911 regulations privacy internet privacy every time a client requests a web page the server can identify the requests ip address and usually logs it also unless set not to do so most web browsers record requested web pages in a viewable history feature and usually cache much of the content locally unless the serverbrowser communication uses https encryption web requests and responses travel in plain text across the internet and can be viewed recorded and cached by intermediate systems when a web page asks for and the user supplies personally identifiable informationsuch as their real name address email address etcwebbased entities can associate current web traffic with that individual if the website uses http cookies username and password authentication or other tracking techniques it can relate other web visits before and after to the identifiable information provided in this way it is possible for a webbased organisation to develop and build a profile of the individual people who use its site or sites it may be able to build a record for an individual that includes information about their leisure activities their shopping interests their profession and other aspects of their demographic profile these profiles are obviously of potential interest to marketeers advertisers and others depending on the websites terms and conditions and the local laws that apply information from these profiles may be sold shared or passed to other organisations without the user being informed for many ordinary people this means little more than some unexpected emails in their inbox or some uncannily relevant advertising on a future web page for others it can mean that time spent indulging an unusual interest can result in a deluge of further targeted marketing that may be unwelcome law enforcement counter terrorism and espionage agencies can also identify target and track individuals based on their interests or proclivities on the web social networking sites try to get users to use their real names interests and locations rather than pseudonyms as their executives believe that this makes the social networking experience more engaging for users on the other hand uploaded photographs or unguarded statements can be identified to an individual who may regret this exposure employers schools parents and other relatives may be influenced by aspects of social networking profiles such as text posts or digital photos that the posting individual did not intend for these audiences online bullies may make use of personal information to harass or stalk users modern social networking websites allow fine grained control of the privacy settings for each individual posting but these can be complex and not easy to find or use especially for beginners photographs and videos posted onto websites have caused particular problems as they can add a persons face to an online profile with modern and potential facial recognition technology it may then be possible to relate that face with other previously anonymous images events and scenarios that have been imaged elsewhere because of image caching mirroring and copying it is difficult to remove an image from the world wide web standards web standards many formal standards and other technical specifications and software 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 bernerslee but some are produced by the internet engineering task force ietf and other organisations 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 stylesheets especially 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 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 ietfs uniform resource identifier uri generic syntax as well as its predecessors and numerous uri schemedefining rfcs hypertext transfer protocol http especially as defined by rfc2616 http11 and rfc2617 http authentication which specify how the browser and server authenticate each other accessibility web accessibility there are methods for accessing the web in alternative mediums and formats to facilitate use by individuals with disabilities these disabilities may be visual auditory physical speechrelated cognitive neurological or some combination accessibility features also help people with temporary disabilities like a broken arm or ageing users as their abilities change internationalisation the w3c internationalisation activity assures that web technology works in all languages scripts and cultures statistics between 2005 and 2010 the number of web users doubled and was expected to surpass two billion in 2010 statistics measuring a websites popularity such as the alexa internet rankings are usually based either on the number of page views or on associated server hits file requests that it receives web caching a web cache is a server computer located either on the public internet or within an enterprise that stores recently accessed web pages to improve response time for users when the same content is requested within a certain time after the original request most web browsers also implement a browser cache by writing recently obtained data to a local data storage device http requests by a browser may ask only for data that has changed since the last access web pages and resources may contain expiration information to control caching to secure sensitive data such as in online banking or to facilitate frequently updated sites such as news media even sites with highly dynamic content may permit basic resources to be refreshed only occasionally web site designers find it worthwhile to collate resources such as css data and javascript into a few sitewide files so that they can be cached efficiently enterprise firewalls often cache web resources requested by one user for the benefit of many users some search engines store cached content of frequently accessed websites electronic publishing internet metaphors internet security lists of websites prestel streaming media web 20 web development tools web literacy webgraph world wide telecom web computer science portalengineering portalinternet portal bernerslee tim bray tim connolly dan cotton paul fielding roy jeckle mario lilley chris mendelsohn noah orchard david walsh norman williams stuart 15 december 2004 architecture of the world wide web volume one version 20041215 w3c bernerslee tim august 1996 the world wide web past present and future fielding r gettys j mogul j frystyk h masinter l leach p bernerslee t june 1999 hypertext transfer protocol http11 request for comments 2616 information sciences institute niels brgger ed web history 2010 362 pages historical perspective on the world wide web including issues of culture content and preservation polo luciano 2003 world wide web technology architecture a conceptual analysis new devices missing or empty url help skau ho march 1990 the world wide web and health information new devices missing or empty url help wikimedia commons has media related to world wide web wikibooks has a book on the topic of nets webs and the information infrastructure the first website early archive of the first web site internet statistics growth and usage of the web and the internet living internet a comprehensive history of the internet including the world wide web web design and development at curlie world wide web consortium w3c w3c recommendations reduce world wide wait world wide web size daily estimated size of the world wide web antonio a casilli some elements for a sociology of online interactions the erds webgraph server offers weekly updated graph representation of a constantly increasing fraction of the www the 25th anniversary of the world wide web is an animated video produced by usaid and techchange which explores the role of the www in addressing extreme poverty vtetelecommunicationshistory beacon broadcasting cable protection system cable tv communications satellite computer network drums electrical telegraph fax heliographs hydraulic telegraph internet mass media mobile phone optical telecommunication optical telegraphy pager photophone prepay mobile phone radio radiotelephone satellite communications semaphore smartphone smoke signals telecommunications history telautograph telegraphy teleprinter teletype telephone the telephone cases television timeline of communication technology undersea telegraph line videoconferencing videophone videotelephony whistled languagepioneers edwin howard armstrong john logie baird paul baran alexander graham bell tim bernerslee jagadish chandra bose vint cerf claude chappe donald davies lee de forest philo farnsworth reginald fessenden elisha gray erna schneider hoover charles k kao hedy lamarr innocenzo manzetti guglielmo marconi antonio meucci radia perlman alexander stepanovich popov johann philipp reis nikola tesla camille tissot alfred vail charles wheatstone vladimir k zworykin transmissionmedia coaxial cable fiberoptic communication optical fiber freespace optical communication molecular communication radio waves transmission line network topologyand switching links nodes terminal node network switchingcircuit packet telephone exchange multiplexing spacedivision frequencydivision timedivision polarizationdivision orbital angularmomentum codedivision networks arpanet bitnet cellular network computer cyclades ethernet fidonet internet isdn lan mobile ngn npl network public switched telephone radio telecommunications equipment television telex wan wireless world wide web category list portal commons wikiproject vteweb syndication history blogging podcasting video blogging web syndication technology types art bloggernacle classical music corporate dream diary edublog electronic journal fake family fashion food health law lifelog litblog mp3 news photoblog police political prayer project reverse travel warblog technologygeneral bittorrent feed uri scheme features linkback permalink ping pingback reblogging refback rollback trackback mechanism conversation threading geotagging rss enclosure synchronization memetics atom feed data feed photofeed product feed rdf feed web feed rss georss mrss rss tv social livemark mashup pooling referencing rss editor rss tracking streaming media standard oml opml rss advisory boardusenet net world wide web let xbel xoxo form audio podcast enhanced podcast mobilecast narrowcasting peercasting screencast slidecasting videocast webcomic webtoon web series anonymous blogging collaborative blog columnist instant messaging liveblogging microblog mobile blogging roblog spam blog video blogging motovlogging mediaalternative media carnivals fiction journalism citizen database online diary search engines sideblog software web directory micromedia aggregation news poll review search video atom atompub broadcatching hashtag newsml 1 g2 social communication social software web slice related blogosphere escribitionist glossary of blogging pay per click posting style slashdot effect spam in blogs uses of podcasting vtefree and opensource softwaregeneral alternative terms for free software comparison of opensource and closedsource software comparison of source code hosting facilities free software free software project directories gratis versus libre longterm support opensource software opensource software development outline softwarepackages audio bioinformatics codecs collaboration configuration management device drivers graphics wireless geophysics health mathematics operating systems programming languages routing statistics television video games web applications content management systems ecommerce word processors android apps ios apps commercial trademarked formerly proprietary community free software movement history opensource software movement organizations events licenses afl apache apsl artistic beerware boost bsd cc0 cddl epl free software foundation gnu gpl gnu lgpl isc mit mpl msplrl python python software foundation license sleepycat unlicense wtfpl zlib types and standards comparison of free and opensource software licenses contributor license agreement copyleft debian free software guidelines definition of free cultural works free license the free software definition the open source definition opensource license permissive software licence public domain viral license challenges binary blob digital rights management hardware restrictions license proliferation mozilla software rebranding proprietary software scolinux controversies secure boot software patents software security trusted computing related topics forking gnu manifesto microsoft open specification promise opencore model opensource hardware shared source initiative sourceavailable software the cathedral and the bazaar revolution os book category commons portal authority control bne xx4576804 bnf cb13319953j data gnd 43638983 lccn sh95000541 nara 10644635 