1. The Command Module (CM): This was the living quarters for the three astronauts during the flight to and from the Moon. It was also the control center for the entire mission, containing the computers, navigation systems, and other instruments needed to operate the spacecraft.

2. The Service Module (SM): The Service Module provided power, propulsion, and other support systems for the Command Module. It housed the main engine, fuel tanks, oxygen tanks, and batteries. The Service Module was jettisoned before the Command Module entered the Earth's atmosphere on the return trip from the Moon.

3. The Lunar Module (LM): The Lunar Module was the spacecraft that landed on the Moon. It consisted of two stages: the Descent Stage, which contained the engines and fuel for landing on the Moon, and the Ascent Stage, which contained the crew cabin and the engines for returning to orbit.