The moon only rarely gets directly in line so that the Earth is between it and the sun. When this happens, we call it a lunar eclipse.

The moon's orbit is inclined to the ecliptic, such that most months, when the moon is full, it does not go through Earth's shadow. The moon passes either above or below the Earth's shadow. So it appears all nice and full, and washes out the stars for amateur astronomers on the night side of Earth. :-?