The WWW has the ability to support many transfer methods (protocols), including HTTP, WAIS, network news, gopher, telnet, anonymous FTP, techinfo, X.500, and whois. To achieve this, the protocol is specified in the URL (Uniform Resource Locator). An explanation of when each protocol should be used is discussed later.
The WWW is an open, non-centralized system of information repositories. Anyone can publish information and any authorized person (as determined by the local system administrator) can read it. Users can publish information by running a server and can read information by running a client such as Mosaic. All clients and servers are connected through the Internet, and communicate using a variety of protocols.
To access information stored in WWW repositories, a client or browser must be used. Mosaic is one of the most popular browsers, both in industry and at NIST. Mosaic operates on the concept of hypertext - which consists of text with links. With hypertext, the computer makes following references as easy as turning the page. This allows readers to escape from the sequential organization of pages and pursue topics which interest them. Hypertext is discussed later in this document.
A document can be retrieved through Mosaic by specifying its URL, which includes the transfer protocol, server, port number, path, and file name. Every file has a unique URL and every URL has a unique file which it points to. In most cases, a document's URL must be known to view it.
Written by: Craig Schlenoff