Network interface
From Computer History Wiki
A network interface is a device controller which connects a computer to a communication network; now, the network is usually a local area network such as an Ethernet.
The interface is generally assigned an address in the network's namespace for interfaces, so that packets intended for a particular host can be sent to its network interface.
Depending on the protocol suite in use, a mapping may be required between the addresses used by the protocol, and the addresses used by the physical network; the Address Resolution Protocol is the usual means for doing this.