Why does the Moon show the same face?
The Moon's rotation period equals its orbital period around Earth. This synchronous rotation keeps approximately the same hemisphere facing us. Saying the Moon does not rotate is incorrect: without rotation, different sides would face Earth during its orbit.
How does tidal locking develop?
Earth pulls differently on the Moon's near and far regions. Tidal deformation and internal energy dissipation affect lunar rotation over long periods, allowing rotation and revolution to become synchronized. Other large moons exhibit similar behavior, but not every orbiting body must reach the same rotational state under all conditions.
The far side and libration
The far side is not permanently dark; it also receives sunlight. Phases describe how much of the visible hemisphere is illuminated. Orbital eccentricity and axial geometry produce apparent rocking called libration, exposing somewhat more than half the surface over time. Much of the far side nevertheless remains invisible from Earth's surface and requires spacecraft observations. Phases, eclipses, and rotation are separate concepts.