A large wide area network created in the 1960s by the U.S. Department of Defense Advanced Research Projects Agency (ARPA, renamed DARPA in the 1970s) for the free exchange of information between universities and research organizations, although the military also used this network for communications. In the 1980s MILNET, a separate network, was spun off from ARPANET for use by the military. ARPANET was the network from which the Internet evolved. See also ALOHA­net, Internet, MILNET.
(Advanced Research Projects Agency Network)
(acronym for Advanced Research Projects Agency Network) Early US network that forms the basis of the Internet. It was set up 1969 by ARPA to provide services to US academic institutions and commercial organizations conducting computer science research. ARPANET pioneered many of today's networking techniques.
It was renamed DARPANET when ARPA changed its name to Defense Advanced Research Projects Agency. In 1975 responsibility for DARPANET was passed on to the Defense Communication Agency.