The Internet that has made its ubiquitous presence felt in a huge number of urban houses today was actually born out of an experiment in the 1960`s, by the US department of defense. The DoD wanted to create a computer network that would continue to function in the event of a disaster, such as a nuclear war. If part of the network was damaged or destroyed, the rest of the system still had to work. That network was ARPANET, which linked U.S. scientific and academic researchers. It was the forerunner of today`s Internet.
After the Soviets launched Sputnik into orbit-it was man`s first foray into space- the then U.S. President Eisenhower, launched an aggressive military campaign to compete and surpass the Russians. ARPA-The Advanced Research Projects Agency was born. It became the U.S. governments research agency for all space and missile research. Then in 1958 NASA was formed, and the activities of the ARPA moved away from aeronautics and focussed mainly on computer science and information processing.
One of the aims of the ARPA was to connect mainframe computers at different universities around the country so that they would be able to communicate efficiently using a common language and a common protocol (protocol in computer language means an agreed upon format for transmitting data between two devices). Thus, the worlds first multiple site computer network was created by ARPANET in 1969.
The original ARPANET eventually grew into the INTERNET based on the concept of multiple independent networks.
All this and more information can be found on www.webopedia.com and many other interesting sites on the internet.