The Advanced Research Projects Agency Network (ARPANET) was the first network to implement TCP/IP, one of the world’s first operational packet switching networks, and was a pioneer of what would become the global Internet. The network was initially funded by the Advanced Research Projects Agency (ARPA, later DARPA) at the U.S. Department of Defense, for use in projects at the U.S. Department of Defense and research laboratories in the U.S.
ARPANET’s packet switching, along with TCP/IP, forms the backbone of the way the Internet works. The package transit was based on the concepts and designs of American engineer Paul Baran, British scientist Donald Davies [The History of Computing Project-2019 and Internet Society-2019], and Lawrence Roberts of Lincoln Laboratory. The TCP/IP communication protocols were developed for the ARPANET by computer scientists Robert Kahn and Vinton Cerf.