2015-08-21
357
The original language of the Internet was uninviting and difficult to use. The potential was exciting, but you had to use a variety of esoteric programs (such as Telnet, FTP, Archie, and Gopher) to locate and download data. The programs were based on the Unix operating system, and you had to know the precise syntax of the commands within each program. There was no common user interface to speed learning. And, even if you were able to find what you wanted, everything was communicated in plain text, as graphics and sound were not available. All of this changed in 1991 with the introduction of the World Wide Web.
The World Wide Web (WWW or, simply, the Web) can be thought of as a very large subset of the Internet, consisting of hypertext and/or hypermedia documents. A hypertext document is a document that contains a hyperlink (link) to another hypertext document, which may be on the same computer or even on a different computer, with the latter located anywhere in the world. Hypermedia is similar in concept, except that it provides links to graphic, sound, and video files in addition to text files.
Either type of document enables you to move effortlessly from one document (or computer) to another. Therein lies the fascination of the Web, in that you simply click on link after link to go effortlessly from one document to the next. You can start your journey at your professor's home page in New York, for example, which may link to a document in the Library of Congress, which in turn may take you to a different document, and so on. So, off you go to Washington DC, and from there to a reference across the country or perhaps around the world.
Any computer that stores a hypermedia document anywhere on the Web, and further, makes that document available to other computers, is known as a server (or Web server). Any computer that is connected to the Web, and requests a document from a server, is known as a client. In other words, you work on a client computer (e.g., a node on a local area network or your PC at home) and by clicking a link in a hypermedia document, you are requesting a document from a Web server.
