The Moon orbits planet Earth.

Many of the other planets in our solar system also have moons. 

The Moon can be seen during the night. This is because it reflects sunlight back towards the Earth. The Moon completes its orbit around the planet Earth in a month. Only one side of the Moon is visible from Earth.

The relative positions of the Sun, the Earth and the Moon determine how much of the Moon is visible. A new moon (1) does not reflect almost any light at all.

A full moon (5) reflects light completely. At other times of the month, only a part of the Moon is visible.

Once in a while, the Moon ends up between the Sun and the Earth. When this happens, the Sun's light is blocked by the Moon. This is called a solar eclipse. Sometimes, the Sun's light can be blocked by the Earth from reaching the Moon. This is known as a lunar eclipse.