According to Wikipedia:
The Apollo Lunar Module (LM, pronounced “Lem”), originally designated the Lunar Excursion Module (LEM), was the lander portion of the Apollo spacecraft built for the USApollo program by Grumman Aircraft to carry a crew of two from lunar orbit to the surface and back. Designed for lunar orbit rendezvous, it consisted of an ascent stage and descent stage, and was ferried to lunar orbit by its companion Command/Service Module (CSM), a separate spacecraft of approximately twice its mass, which also took the astronauts home to Earth. After completing its mission, the LM was discarded. It was capable of operation only in outer space; structurally and aerodynamically it was incapable of flight through the Earth’s atmosphere. The Lunar Module was the first manned spacecraft to operate exclusively in the airless vacuum of space. It was the first, and to date only, crewed vehicle to land anywhere beyond Earth.
Six such craft successfully landed on the Moon between 1969 and 1972. A seventh provided propulsion and life support for the crew of Apollo 13 when their CSM was disabled by an oxygen tank explosion en route to the Moon.
The LM’s development was plagued with problems which delayed its first unmanned flight by about ten months, and its first manned flight by about three months. Despite this, the LM eventually became the most reliable component of the Apollo/Saturn space vehicle, the only component never to suffer a failure that significantly affected a mission.
Image retrieved from: NASA
Image archive from: NASA website