Source: The National Aeronautics and Space Administration (NASA)

We divide the moon's orbital cycle into several phases.

The lunar month is the 29.53 days it takes to go from one Moon phase to the next. During the lunar month, the Moon goes through all its phases. 

At the New Moon, the moon is lined up between the Earth and the Sun. We see the side of the moon that is not being lit by the Sun. When the Moon is exactly lined up with the Sun, we experience an eclipse.