A research and development arm of the U.S. Department of Defense (DOD). ARPA was responsible for the development of the Advanced Research Projects Agency Network (ARPANET), an experimental network that was designed to connect computers in disparate geographic locations and allow researchers to share information and other resources. In the mid 1970s, ARPA became the Defense Advanced Research Projects Agency (DARPA). DARPA continued to operate ARPANET, which eventually transformed into a packet-switched network that used the TCP/IP protocols and subsequently laid the groundwork for the development of the network we now know as the Internet. merican Registry for Internet Numbers (ARIN) The newly-formed, non-profit organization established to manage the allocation of Internet Protocol (IP) numbers for the areas currently served by the InterNIC's Registration Services: the Americas, the Caribbean, and sub-Saharan Africa. The National Science Foundation (NSF) approved the establishment of ARIN on June 24, 1997.
Agency of the U. S. Department of Defense that promotes exploratory research in areas that carry long term promise for military applications. ARPA funded the major packet switching experiments in the United States that led to the Internet, particularly the ARPANET.