Why does te moon have different shapes?

The Moon appears to have different shapes, or phases, due to its position relative to the Earth and the Sun. As the Moon orbits Earth, varying portions of its surface are illuminated by sunlight, creating phases such as new moon, crescent, first quarter, gibbous, and full moon. These phases occur in a predictable cycle, taking about 29.5 days to complete. The changing shapes are simply a result of observing the illuminated part from our perspective on Earth.