The Moon goes through eight distinct phases in a cycle that lasts about 29.5 days. These phases include the New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter, and Waning Crescent. The changes in appearance are due to the relative positions of the Earth, Moon, and Sun. During the New Moon, the Moon is not visible from Earth, while the Full Moon appears fully illuminated. As the Moon orbits the Earth, sunlight reflects off its surface, creating the various phases we observe. Each phase has unique characteristics and can influence tides and natural phenomena.