The term 'moon stages' is used to describe the different PHASES of the moon. The most common PHASES are new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, and waning crescent. Each phase is associated with a particular shape of the moon as it appears in the night sky. The term 'PHASES' is often used interchangeably with 'stages' when referring to the moon's cycle.