There are two main types of central air conditioning systems. The first is a split system. The second type is a packaged unit. Split systems have two main components: the compressor and the evaporator. The compressor stays outside your home. The evaporator is an indoor unit. It is often rolled into a cabinet with a furnace as well.
In packaged units, the entire A/C system is in one unit. That unit is installed outside, usually on a roof or next to the home’s foundation. This type of air conditioner may also have electric heating or natural gas heating included.