is the name given to the hundreds of thousands of computer networks worldwide which are linked by 'gateways' to form a single global network. The network allows information to pass from one machine to another - there is no central point 'controlling' or 'storing' all the information on the Internet.
	is an application of the Internet. Originally it was used mostly by the academic staff of universities to share research, and it could only display text. However, in recent years as the technology has advanced, pictures, sound and video have appeared on the World Wide Web. As a result it is fast becoming an essential means of relaying information for government, educators, advertisers and individual people.
	is one of a number of means of sending and receiving messages over the Internet. It allows you to type and send a message to someone else, or a number of other people.
	are another way of talking to people online, although these are mainly focused on particular topics of interest. Discussion groups include USENET Newsgroups, and the Mailbase service which provides e-mail discussion lists for UK Higher Education.