The Moon is the only satellite of the Earth. It does not have light of its own, but it reflects the sunlight. The shape of the Moon changes every night. The various phases of the Moon can be understood as under:
1.The visible portion of the Moon increases when it moves from the phase of new moon to the phase of full moon. This is known as wax.
2.The visible portion of the Moon decreases when it moves from the phase of full moon to the phase of new moon. It is known as wane.
Waxing and waning constitute a phase of the moon.
The half portion of the Moon always appears dark. Since the view from the Earth keeps on changing, we see the bright part of it.

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