This book provides readers with comprehensive details on how the WWW works, complete with definitions and standards. It discusses the latest versions of the transfer protocol (HTTP 1.1), the description language (HTML 4.0), the foundations of the description language (SGML and XML), style sheets (CSS1), web servers, and security (SSL and CGI). Issues of importance for the future development of the WWW are discussed, including virtual reality (VRML), portable network graphics (PNG), and MathML.