Interphone vs. Intercom — What's the Difference?

A telephone used in a small closed system of telephones

An intercom ("intercommunication device") or interphone is a stand-alone voice communications system for use within a building or small collection of buildings, functioning independently of the public telephone network. Intercoms are generally mounted permanently in buildings and vehicles.

Intercom

An electronic intercommunication system, as between two rooms.

A telephonic intercommunication system linking different rooms in a building or ship etc

An electronic communication system, especially one between rooms in a building.

(ambitransitive) To communicate (with) by intercom.

A communication system linking different rooms within a building or ship etc