The Moon is tidally locked to Earth. It rotates once for every orbit. This synchronization took millions of years. Gravitational forces caused it. The far side looks very different. It has fewer maria and thicker crust.
This matters because it affects observation. Humans didn’t see the far side until 1959. Exploration changed perception.
It also demonstrates tidal locking. Many moons and exoplanets behave similarly. The Moon is a textbook example.
The Moon’s far side was first photographed by a Soviet spacecraft.
[NASA, nasa.gov]