Multi room audio is simply your favorite music in each room of your home and yes you can listen to different things at the same time and of course play the same thing and of course adjust the volume level in each room.
How does Multi-Room Audio work ? Well that really depends on what system you purchase the majority of them now have apps for your iPhone, iPad, android phone or tablet and of course PC control.
Were does the music come from ? Again it depends on what system you are using but most systems use an external NAS drive system, Spotify, Apple music and of course your phone or tablet
Can I have music I my garden ? Yes of course you can have music in you garden, pool, sauna and steam room we just use environmental speakers these are built to withstand snow, rain, salt and temperature extremes