ARPANET Network Definition
In the mid-1960s, at the height of the Cold War, the DoD wanted a command and control network that could survive a nuclear war. Traditional circuit-switch telephone networks were considered too vulnerable, since the loss of one line or switch would certainly terminate all conversations using them and might even partition the network. To solve this problem, DOD turned to its research arm, ARPA (later DARPA, now ARPA again), the (Defense) Advanced Research Projects Agency.
ARPA was created in response to the Soviet Union's launching Sputnik in 1957 and had the mission of advancing technology that might be useful to the military. ARPA had no scientists or laboratories, in fact, it had nothing more than an office and small budget. It did its work by issuing grants and contracts to universities and companies whose ideas looked promising to it.
By 1983 this process of bringing together different new technologies resulted in a stable and successful network. During the 1980s, additional networks, especially LANs, were connected to the ARPANET. However, by 1990, the ARPANET had been overtaken by newer networks that it itself had spawned, so it was shut down and dismantled.
- Local Area Network