New Moon

• The key to understanding the moon is realizing that, like the earth, it is moving around another object and it also rotates, leaving half of the moon in daylight while the other half is in darkness. The "new moon" is a phase of darkness at night because the moon is actually directly between the earth and sun, meaning that it can only be faintly seen during the day. The side facing the earth is completely dark, making the new moon very faint and difficult to spot.
  
  

Crescent Moon

• Just a few days past the new moon, you can view the "crescent moon." From the earth's vantage point, the moon looks like a sliver of light. The majority of the moon's face you're viewing is still in darkness. At this time, the moon has rotated about the earth to the point where it can be viewed just after sunset to the west and prior to sunrise in the east.
  
  

First Quarter Moon

• The "first quarter moon" appears to be a half-lit moon, meaning that the moon has moved into a position that is roughly at 90 degree angle with the earth and the sun. The "Gibbous moon" occurs after this when the moon is not full, but is also more than half lit up.
  
  

Full Moon

• The "full moon" signifies a period of time where the moon's orbit has taken it to the direct opposite position from where it was during the new moon. During the full moon phase, the moon is completely lit up in the night sky and is viewable throughout most of the night.
  
  

Reversing Course

• The cycle then continues, appearing to go in reverse, as it will hit the gibbous phase and then the "last quarter" phase, where the moon will appear to be identical to the first quarter phase, except that it will be located at the opposite position in the sky. When the moon hits the new moon phase again, it will continue the cycle.