Multi Zone in modern systems means 2 zones: Main Zone and Zone 2. This allows for systems, as an example, to watch cable, sat, or streaming video on main system while streaming a music service to Zone 2. Today’s systems are network controlled, meaning that functions like what you hear, where you hear it, and how loud it is are all controlled by your phone and/or tablet. This is primarily a function for Zone 2 as the common methods of controlling Main Zone are by using a remote in the main TV area.