Multiroom Audio normally refers to a domestic system allowing different sound sources to be played and controlled in different rooms. It will usually involve a media rack in a main position in the house, (eg. the lounge), with separate speaker lines to each room and optionally a CAT5 cable to each room for a remote control plate. Additional inputs can also be installed in other rooms for local playback. This extensive wiring is best suited for a new build where the walls and ceilings are unfinished. Fortunately, for retro-fitting a multiroom system there are a couple of other solutions. The use of WiFi and wireless links with the possibility of controlling your system from your phone or tablet or using the existing mains wiring in the house.
In commercial situations, there is a separate product line more often referred to as Multizone Audio. Similarly, the system routes different audio sources to different areas or zones but you also have the facility of multizone paging microphones and the ability to instantly reconfigure the zones to suit the event. Systems range from a simple two zone set up with up to six audio inputs and a microphone to a complex system with multiple zones, several paging microphones and numerous remote controls.