This occurs when the moon is positioned between the earth and the sun. The sunlight is on the backside of the moon, the half that we cannot see. The new moon is a time to manifest positive energy that you want to bring into your life.
The waxing moon is the period from the new to the full moon. The moon grows from right to left (waxing crescent to full) this is a time to draw something to you.
The earth, moon and the sun are in approximate alignment, just as the new moon. That is the moon is on the opposite side of the earth, the entire illuminated part of the moon is facing us. The full moon is a time to release all the negativity from your life.
The waning moon is the period from the full to the new. The moon decreases from right to left (full to waning crescent) this is a time to release.