Like much of the development of the internet, it was originally thought of during development conducted by the Defense Advanced Research Projects Agency (DARPA), a research and development branch of the US military, in the 1960s. After the development of ARPANET in 1969, DARPA worked on various other technologies related to data transmission. Robert E. Kahn worked on the satellite packet networks and ground-based radio packet networks while working for DARPA in the early 1970s, where he noted the usefulness of being able to communicate using both. Vinton Cerf, the developer of the ARPANET Network Control Program, joined Kahn and worked on a model for network connection for the next generation of ARPANET.
By 1973, they had developed a version where the differences between network protocols was hidden by a common internetwork protocol, making the hosts responsible for network reliability. The specification for this protocol is what gave rise to the term internet, initially used as shorthand for internetwork. This reduced the role of the network, allowing any network to connect with any other no matter the characteristics.