The original birthplace of the Internet was the United States Department of Defence. It was known then as the Arpanet (Advanced Research Projects Agency – ARPA). It involved a network of 4 computers at different locations throughout the U.S. and was originally designed to allow scientists to share data and to access remote computers. It was a decentralised military research network. It would be used to maintain command and control over U.S. bombers and missiles in the event of a nuclear attack. The decentralisation enabled the military to maintain control over nuclear arms if any of the 4 locations were attacked.

The information was sent via a packet switched network. Using this system, data is sent from computer to computer and labelled to indicate its origin and destination.

In 1969 the first hosts (4 Universities) are linked. E-mail quickly becomes the most popular application – used to discuss and collaborate research projects and topics of interest.

Between 1974-1981 The Arpanet continues to grow and gradually begins to move away from its military and research roots. The commercial version of the Arpanet goes on-line, giving the general public get a first glimpse of how computer networking can be used in daily life. Growth continues and in 1982 the term Internet is used for the first time. A common language of all Internet computers is developed and the Internet as we know it today is born.

During the mid 80’s many companies joined the Internet for the first time. Corporations begin using it to communicate with each other and with their customers.

By 1988 the Internet is an essential tool for communications but concerns about privacy and security begin to arise. On 1 November 1988 this concern becomes a reality when a programme called the "Internet Worm" temporarily disables 6,000 of the 60,000 host computers. As a result the Computer Emergency Response Team (CERT) is formed, to address such security issues.

By 1989 there are more than 100,000 Internet hosts and in 1990 the Arpanet is decommissioned, leaving behind the network of over 300,000 hosts which it has become – THE INTERNET.

 The Internet as we know it today is the open interconnection of computer networks that enables computers and the programmes they run to communicate directly.

The term Internet/Net is usuaally applied to the global, publicly accessible network.

Information travels across computer networks via the Internet backbone. The backbone contains the links that provide the main connections between its connected networks.

A computer connected to a network is called an Internet host. This host is provided with a unique number; an Internet Protocol (IP) address. The Domain Name Service (DNS) gives a name to this address e.g. microsoft.com – com refers to a commercial organisation.

Many kinds of networks and services are connected via systems called gateways.

E-mail (electronic mail) allows a message to be sent from one person to another, or to many others, via computer.

The World Wide Web offers vast amounts of easily accessible information across the Internet.