The corridor where WWW was born. CERN , ground floor of building No. By , the global Internet began to proliferate in Europe and the Domain Name System upon which the Uniform Resource Locator is built came into being. There is no reason, the proposal continues, why such hypertext links could not encompass multimedia documents including graphics, speech and video, so that Berners-Lee goes on to use the term hypermedia. By Christmas , Berners-Lee had built all the tools necessary for a working Web: The first web site,  which described the project itself, was published on 20 December Jones stored it on a magneto-optical drive and on his NeXT computer.
As another example of such confusion, several news media reported that the first photo on the Web was published by Berners-Lee in , an image of the CERN house band Les Horribles Cernettes taken by Silvano de Gennaro; Gennaro has disclaimed this story, writing that media were "totally distorting our words for the sake of cheap sensationalism. Accounts differ substantially as to the date of this event.
Both Nelson and Engelbart were in turn inspired by Vannevar Bush 's microfilm -based memex , which was described in the essay " As We May Think ". 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: 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 non-proprietary, making it possible to develop servers and clients independently and to add extensions without licensing restrictions. Funding for Mosaic came from the U. Mosaic's graphical user interface allowed the Web to become, by far, the most popular Internet protocol.
By the end of , the total number of websites was still relatively small, but many notable websites were already active that foreshadowed or inspired today's most popular services. Connected by the Internet, other websites were created around the world. This motivated international standards development for protocols and formatting. Berners-Lee 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 easy-to-use and flexible format. It thus played an important role in popularising use of the Internet. 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 usually accessed using HTTP , which is one of many Internet communication protocols.
The web browser then initiates a series of background communication messages to fetch and display the requested page.
In the s, using a browser to view web pages—and to move from one web page to another through hyperlinks—came 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: The browser resolves the server name of the URL www. This lookup returns an IP address such as 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 The content of the HTTP request can be as simple as two lines of text: If the web server can fulfil the request it sends an HTTP response back to the browser indicating success: Many web pages use HTML to reference the URLs of other resources such as images, other embedded media, scripts that affect page behavior, and Cascading Style Sheets that affect page layout. 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[ edit ] 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: 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 , is the best known of such efforts.
Client-side script is delivered with the page that can make additional HTTP requests to the server, either in response to user actions such as mouse movements or clicks, or based on elapsed time. The server's responses are used to modify the current page rather than creating a new page with each response, so the server needs only to provide limited, incremental information.
Multiple Ajax requests can be handled at the same time, and users can interact with the page while data is retrieved. Web pages may also regularly poll the server to check whether new information is available.
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 nxoc Many established websites still use the prefix, or they employ other subdomain names such as www2, secure or en for special purposes. Many such web servers are set up so that both the main domain name e. The use of a subdomain name is useful for load balancing incoming web traffic by creating a CNAME record that points to a cluster of web servers.
Since, currently, only a subdomain can be used in a CNAME, the same result cannot be achieved by using the bare domain root. For example, entering 'microsoft' may be transformed to http: This feature started appearing in early versions of Firefox , when it still had the working title 'Firebird' in early , from an earlier practice in browsers such as Lynx.
Stephen Fry, in his "Podgrams" series of podcasts, pronounces it wuh wuh wuh. Tim Berners-Lee's web-space states that World Wide Web is officially spelled as three separate words, each capitalised, with no intervening hyphens.
Scheme specifiers[ edit ] The scheme specifiers http: They specify the communication protocol to use for the request and response. Web browsers usually automatically prepend http: Web security[ edit ] 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.
Internet privacy Every time a client requests a web page, the server can identify the request's 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 server-browser 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 information —such as their real name, address, e-mail address, etc. 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 web-based organization 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 website's terms and conditions and the local laws that apply information from these profiles may be sold, shared, or passed to other organizations without the user being informed.
For many ordinary people, this means little more than some unexpected e-mails in their in-box 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. These website's leaders believe 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.
On-line 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.
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. 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.
Usually, when web standards are discussed, the following publications are seen as foundational: These define the structure and interpretation of hypertext documents. 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.
HTTP Authentication, which specify how the browser and server authenticate each other. 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, speech-related, cognitive, neurological, or some combination. Accessibility features also help people with temporary disabilities, like a broken arm, or ageing users as their abilities change. The World Wide Web Consortium claims that it is essential that the Web be accessible, so it can provide equal access and equal opportunity to people with disabilities. Access by everyone regardless of disability is an essential aspect.
A more recent study, which used web searches in 75 different languages to sample the Web, determined that there were over