The stages of the development of the moon are called phases of the moon or its phases. These are the phases during which the moon passes. Its visual form changes from the crescent phase, then becomes a badr, then its final form is called a machete. These shapes come as a result of the moon's rotation around the earth. A full Arabic month during which the phases of the moon are changed periodically. Its shape changes as a result of changes in the relative positions of the moon, the earth and the sun. The first half of the moon is illuminated by the sun - except for lunar eclipses - and the moon is bright or bright, but only part of the illuminated half that is visible to the viewer can change from 100% (full moon) to 0% Al-Muhaq). It is then called the boundary that separates the illuminated half ball and the other half that is not lit.