In this tidal locking, the Moon swings slightly back and forth and up and down about this equilibrium position. These motions are called libration. In this time lapse animation you see one complete lunar cycle.
The far side
Before the Space Age, nobody had ever seen the far side of the Moon. Only recently, since we can send orbiters around the Moon, are we able to see the far side of the Moon.
Do not call this side the "dark side" as is sometimes done, because this has nothing to do with Sunlight on the Moon.
The first photograph of the far side was taken by the Soviet Luna 3 probe in 1959. Apollo astronauts were the first humans to see the far side with their own eyes, for the first time from Apollo 8 in 1968.
The photo to the right shows part of the familiar near side at the left
and a large part of the heavily cratered far side to the right.