Definition
Advanced Research Projects Agency Network
The Advanced Research Projects Agency Network (ARPANET) was an early packet-switching network and the first to implement the TCP/IP protocol suite. It served as the technical foundation for the Internet.
Origins
ARPANET was funded by the Advanced Research Projects Agency (ARPA) of the United States Department of Defense. The first node became operational at the University of California, Los Angeles in October 1969.
Significance
The network initially connected research institutions and demonstrated the viability of packet switching and distributed communication. It grew to link dozens of computers, including those running the TENEX operating system, and became the testbed for early experiments in networked computing — including the propagation of Creeper, the first known malware.