"In late , civilian contractors developed the network technology that grew into the Internet. The first network to use the packet switching technology was not actually built until , however, and it contained only four nodes. This network was used by the Department of Defense and was known as . The first ARPANET transmission occurred when Kleinrock logged on from a computer connected to a Stanford computer and typed the word "login." Although the system crashed as he typed in the "g" of "login," the Internet revolution was born. By 1973, a total of 37 nodes were in operation."