Meaning – The term MILNET, refers to the military network that was originally part of ARPANET. It was partitioned from ARPANET in 1984. MILNET provides a reliable network service for military installations.

MILNET was used for unclassified military communication. It remained connected to ARPANET at a small number of gateways so that it could exchange email, but could be easily disconnected in case of security concerns.

The ARPANET remained in service for the academic research community, but direct connectivity between the networks was severed for security reasons. Gateways relayed electronic mail between the two networks. BBN Technologies built and managed both the MILNET and the ARPANET and the two networks used very similar technology.

Example of usage“During the 1980s the MILNET expanded as part of the Defense Data Network, a worldwide set of military networks running at different security levels. In the 1990s, MILNET became the NIPRNET.”