World Wide Web
World Wide Web (WWW or W3), collection of globally distributed text and multimedia documents and files and other network services linked in such a way as to create an immense electronic library from which information can be retrieved quickly by intuitive searches. The Web represents the application of hypertext technology and a graphical interface to the Internet to retrieve information that is contained in specially formatted documents that may reside in the same computer or be distributed across many computers around the world. It consists of three main elements. The Hypertext Markup Language (HTML) comprises the programming codes, or tags, that define fonts, layouts, embedded graphics, and links (hyperlinks) to other documents accessible via the Web. The HyperText Transfer Protocol (HTTP) defines a set of standards for transmitting Web pages across the Internet. The Uniform Resource Locator (URL) is a standardized naming convention for identifying a Web document, image, or other file by its location, in a sense the address of a file. The result is called the Web because it is made up of many sites, all linked together, with users traveling from one site to the next by clicking a computer's pointing device on a hyperlink.
Web sites, also called Web pages, are really Internet sites that all use the same techniques and HTML tags to create multimedia documents with hypertext links. Each Web page can contain many screens or printed pages of text, graphics, audio, and even video, and the starting point for any Web site is called its home page. Although each page is an Internet site, it must be accessed via a special program called a Web browser, which can translate the HTML into the graphical images, text, and hypertext links intended by the creator of the page.
Interactive television is a generic term that encompasses a variety of Web-related television technologies and products. Typically, a home television receiver and a telephone line are connected through a small appliance that accesses the Internet through the telephone line and converts the downloaded Web pages into a form that can be displayed on the receiver. A remote control interface allows the user to navigate through the Web and select the information to be displayed.
Ted Nelson, an American computer consultant, had promoted the idea of linking documents via hypertext during the 1960s, but the technology required was not to be available for another 20 years. The foundation of what we now think of as the Web originated with work done on the retrieval of information from distributed systems by Tim Berners-Lee at CERN during the 1980s. This culminated in the introduction of a text-only interface, or browser, to the scientific community in 1990 and to the public in 1991. Because of the difficulty of using this version, acceptance outside the scientific and academic communities was slow. Marc Andreessen, an undergraduate student working at the National Center for Supercomputing Applications (NCSA), developed a graphical browser for the Web, introducing a UNIX version in 1993. Versions for the Windows and Macintosh operating systems followed in 1994, and acceptance of the World Wide Web blossomed quickly. In the late 1990s the development of improved browsers with greater multimedia functionality, security, and privacy, as well as more powerful search engines capable of indexing the ever greater information on the Web, led to the commercialization of the Internet (see e-commerce).
See P. Whitehead and R. Maran, Internet and World Wide Web: Simplified (2d ed. 1997); E. Wilde, Wilde's WWW: Technical Foundations of the World Wide Web (1997); A. Glossbrenner and E. Glossbrenner, Search Engines: For the World Wide Web (2d ed. 1998); S. Western, The Complete Beginner's Guide to the World Wide Web (1998); T. Berners-Lee and M. Fischetti, Weaving the Web (1999).
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