The Internet was invented in the late 1960s by the US Defense Department's Advanced Research Projects Agency. In 1969, there was a network of just four mainframe computers. A mainframe computer is a large, powerful computer, shared by many users. The idea of the electronic mailbox was born when users looked for a way to talk to each other electronically. By 1984,the Internet had begun to develop into the form we know today. Electronic mail is much faster than traditional mail, because once the message is typed out, it arrives in the electronic mail box of the recipient within minutes. It's better to use e-mail to contact friends rather than phone them, because e-mail is cheaper for long distances than the phone. People can share their interests through the Internet and it makes it very easy to exchange ideas and information.
The fax machine is a very convenient aid to contact companies and friends because messages are transmitted immediately. Fax machines work like photocopiers. They make a copy of a document and then send it down a telephone line to another fax machine. In this way they can send and receive information from each other. You can send any kind of thigs by fax, but it is more expensive than e-mail.