Well, there's a single outdoor condenser, which acts like the motor for the entire system. This is what powers your indoor units and what chills the refrigerant as it cycles back and forth. This condenser is then connected to each of the indoor air handlers.
Each room, or "zone" will have its own indoor air handler. Your HVAC professional can help you decide which size units make the most sense for your space, but you can also find a helpful guide on each product page.
(Please be aware that only a certified professional who can measure your space will be accurate in providing a load estimate.)
The refrigerant flows from the condenser through line sets, which are semi-flexible pipes generally made from copper. The line sets connect to the indoor unit, which then uses the refrigerant to blow cold air into the room. In cold weather, the process is reversed, and the heat pump action delivers energy efficient warm air.