The World Wide Web (WWW or W3)
The WWW is the multimedia part of the Internet displaying a hyper text type of structure and search facilities. It was first developed for sharing documents between the nuclear physicists of the European Particle Physics Laboratory (CERN) in Switzerland in 1989, but the first commercial Web Software by Next in 1991, popularised this form of access to the Internet. The main characteristics of the WWW organisation and structure are:
- Organising documents into pieces of information (pages) using a set of rules which tag and format the documents, The Hypertext Mark up Language (HTML).
- Every individual document or page is assigned a unique address, called Uniform Resource Locator (URL).
- Each URL can be linked with a hypertext type link to other URLs and even pieces of information within each document (buttons) can be linked to URLs to other pieces of information.
- These documents can be searched through interactive interface programs which allow users to browse and navigate through the documents and are called Web browsers.
The communication between The Web browsers and the Web servers is regulated by a common language using a standardised set of rules called Hypertext Transfer Protocol (HTTP). The H'I'I"P allows the interpretation of the HTML signs within each Web page in order to display correctly the page and to enable the transfer of files. A client programme or Web browser provides the user with control over the retrieval process and also over the links to be activated.
It is to be noted that individuals and organisations create home pages ,to present their own information or services. A collection of home pages located on the same server is called a Web site. Access to these pages is via the uniform Resource Locator (URL) using a browser. Some examples of browsers are Lynx, Netscape, etc. these addresses link the user to the host computer and their individual files, these are then displayed on the user's terminal (workstation). With the help of appropriate software users can read documents, view pictures, listen to sound, and retrieve information.
The hypertext structure of the Web means that retrieval is done through following the links between different web pages through browsing and navigation. In indexing terms, the hyperlinks on the WWW that form the basis of the browsing network are uncontrolled but humanly assigned indexing terms. There is no general control over which terms should be used as hyperlinks, but each hyperlink is individually coded by the creator of HTML (Hypertext Markup Language). It may be mentioned here that though browsers encourage movement through a network of linked documents, browsing is not an efficient approach to the identification of specific information. Different search tools have been devised in order to assist people in finding information on the largest repository of documents in the world. These search tools can be divided into two main categories: 'subject directories' and 'search engines.'