7.2 The main concepts behind WWW

WWW is officially described as an Internet-wide distributed hypermedia information retrieval system which provides access to a large universe of documents. It began as a set of simple protocols and formats and was originally seen as a test-bed for various sophisticated hypermedia and information retrieval concepts. WWW, like many other applications on global networks, uses a client-server model. These clients (called Web browsers if they are intended for interactive use) are nothing more than collections of fairly simple programs which can send requests for documents to WWW servers. On the other hand, WWW servers are programs that, after they receive requests, send back the appropriate answers -- either documents or error messages.

To make this flow of information possible, three major `standards' and conventions were defined. First, a consistent address system using a compact syntax for a Uniform Resource Locator (URL) was defined. In addition to other protocols which may be used with WWW a new protocol, the fapHypertext Transfer Protocol (HTTP) was defined, giving performance and features not otherwise available. A set of data formats can be used in which data can be transferred. One of them was a new data format, the HyperText Markup Language (HTML), which has become the main format for transmitting hypertext. These three most important elements of WWW, namely, URL, HTTP and HTML will be explained in the following subsections.

7.2.1 HyperText Transfer Protocol (HTTP)

7.2.2 The Uniform Resource Locator (URL)

7.2.3 HyperText Markup Language (HTML)

7.2.4 HTML editors