the phases of the moon are caused by its position relative to the earth and the sun. the moon phases include first quarter, waxing cresent, new moon, wanning cresent, third quarter, wanning gibbous, full moon, and the waxing gibbous. how this works is the sun shines on a certain part of the moon, the side the sun was shining on is what we see at night. the other part of the moon that is not being shined on is facing away from the sun so it makes it look like part of the moon is missing, but it is really just in the dark. the moon fases are very important with out them the oceans waves will not move and more importantly the moon will not be as interesting!