The original intent was to construct a network that would continue to function even if a large portion of it were destroyed, for example, in the event of nuclear war. The Internet is now a public, cooperative, and self-sustaining facility accessible to tens of millions of people worldwide. Physically, the Internet uses a portion of the total resources of the currently existing public telecommunication networks.
Electronic mail is the most widely used application on the Net.
More recently, Internet telephony hardware and software allows real-time voice conversations on the Net. Its outstanding feature is hypertext, a method of instant cross-referencing. When you select one of these words or phrases, you will be transferred to a site relevant to the word or phrase. If you move the pointer over a spot on a Web site and the pointer changes into a hand, this indicates that you can click and be transferred to another site. Using the Web, you have access to millions of pages of information.