The Moon doesn't actually produce its own light. It shines because it reflects sunlight.

Think of it like a mirror:

* The Sun emits light, which travels through space.

* When sunlight hits the Moon's surface, some of it bounces back towards us, making the Moon appear bright.

The different phases of the Moon (new moon, crescent, full moon, etc.) are caused by the changing angles at which we see the sunlit portion of the Moon from Earth.