If you've ever looked up at the moon and noticed that the shape was not always round, you're not alone! The moon rotates on its axis as it orbits around Earth, so sometimes it will look more like a crescent, a quarter circle, or a half-moon.
The moon is the only natural satellite of the earth and it moves around the earth .Because of earths rotation and revolution around the sun ,moon takes 29.5 days to go through its eight phases and that is called as a lunar month.Moon does not have light on its surface’s.It receives the sunlight and reflects it back to earth which we call as the moonlight. As the earth and moon are constantly moving the moon receive sunlight on different parts and hence it looks like changing shapes every day. Full moon is when the moon is lighted full circle and new moon is the phase when moon is completely dark.New moon is considered to be the first phase of the lunar cycle.after that it starts brightening gradually till it reaches the next full moon.
A full Moon occurs when the Moon is in its orbit and that Earth comes between the Moon and the Sun.Moon is completely lit and looks like a complete circle from the earth. New moon occurs when the moon comes in between the earth and sun and the lit side is away from the view of earth.SO it is completely dark.it takes approximately 15 days from one full moon to a new moon,which make a fortnight.
From the New moon we see more of the moon each night and this is called Waxing Moon. After the moon reaches the Full moon it starts getting smaller.This is called Waning Moon.