Yep, the compressor and fan motor(s) run from the shoer poser or generator on 120 VAC (volts alternating current). But on most of the A/C units, the control circuit is 12 VDC (volts direct current) or battery. The RV has a converter that converts 120 VAC to 12 VDC and charges the battery(ies).
If you have an INVERTER, it will convert 12 VDC to 120 VAC, usually to run a residential fridge or the TV and electronics.
A few years ago I saw a book from the Dummies series called RVs for Dummies. It was a pretty basic, but was a good starting point.