The World Wide Web makes all these previous services look like stone tablets and smoke signals. In fact, the Web is better than that! It can read stone tablets and send smoke signals too!
The World Wide Web service is made up of several components. Client programs (e.g. Mosaic, Lynx etc) access servers (e.g. HTTP Daemons) using the protocol HTTP. Servers hold data, written in a language called HTML. HTML is the HyperText Markup Language. As indicated by its name, it is a language (in other words it consists of keywords and grammar for using them) for marking up text that is hyper!
The pages in the World Wide Web are held in HTML format, and delivered from WWW servers to clients in this form, albeit wrapped in MIME (Multipurpose Internet Mail Extensions) and conveyed by HTTP. HTTP is the HyperText Transfer Protocol.
The way this all fits together is the subject of the rest of this book.