Communication system and Public address system

Communication system noun - A system for communicating.

Public address system and communication system are semantically related. In some cases you can replace phrase "Public address system" with "Communication system", this phrases are similar.

Public address system noun - An electronic amplification system used as a communication system in public areas.

Communication system and public address system are semantically related. Sometimes you can use "Communication system" instead a noun phrase "Public address system".