An ethernet interface is often referred to as a port. A computer port is vaguely in the same spirit as an airport and seaport: it's a place that a lot of traffic passes through. Port is a lot easier to say than "ethernet interface" and is used more.
Computers in the LIC (Larg's Internet Cluster) have a high port density compared to domestic computers. Port density is the number of ports on each computer. A PC in a typical home network has one interface. A LIC PC has at least three.
Each IBM PC has three or four ethernet interfaces. The Linux OS (Operating System) names these eth0, eth1, eth2 and, if it exists, eth3. Each PC arrived with eth0 only. I bought NICs (Network Interface Cards) to provide the rest.
|LIC topology: ethernet interfaces|