Air Conditioners are basically a simple design that have not changed in many years.  There are two main types of units; a package unit and a split system.  Within your unit you could have a heat pump, a gas pack or furnace, or an electric furnace or heat strips.

    Here are some details about how a unit works and what makes up a unit. In normal cooling mode, air from inside your home goes up in the return grill (where the filter is), goes across an indoor evaporative coil, through the blower, and back out through the supply registers (either in the ceiling of every room or mounted on the side of the wall). When air gets passed through the indoor coil, or evaporator coil, the heat in the air is removed by the coil and placed in the refrigerate. The refrigerate takes the heat that was removed from the air and sends it to the compressor.  In the compressor it does what it sounds like.  It compresses the refrigerate into high pressure. After the refrigerate is compressed, it goes to the outdoor coil or the condenser coil. When it gets to the outdoor coil the heat is removed by the outdoor fan motor.  The outdoor fan motor, or the condenser motor, pulls air through the outdoor coil removing the heat from the refrigerate and blowing it out of the unit. When you place your hand over the fan while it is running you notice how much hotter it is than the air around it. The temperature difference is the heat that was removed from your home. In the normal cooling mode that is how an air conditioner works whether you have one compressor or five. If you have a heat pump, the heating cycle is the same as when you are in the cooling mode just in reverse.