The Moon is the one thing that orbits our Earth. It takes approximately 28 days [which is known as a Lunar Month]. If we had no Moon, it would take 1,000 days for a year. The Moon does not change its shape, it’s covered by the Sun. This diagram will show you.
Did you know the Moon causes tides on Earth?
The Moon causes tides by the gravitational pull that makes the water stretch so basically think of the moon as a magnet and the tides on Earth as Metal. When the Earth is turning around on its axis and when the Moon is facing the Earth on the East, two tidal bulges are created on opposite sides of the Earth due to the moon's gravitational force and inertia’s counterbalance. The gravitational attraction between the Earth and the Moon is strongest on the side of the Earth that happens to be facing the Moon, simply because it is closer. This was scientifically proved by Ocean Service.