Here's why:
* Full Moon: The entire illuminated side of the Moon faces the Earth, making it appear round.
* Waning Gibbous: As the Moon orbits the Earth, the illuminated portion gradually decreases. This phase is when more than half of the Moon's face is still lit, but less than a full circle.
Think of it like a pie:
* Full Moon: The entire pie is visible.
* Waning Gibbous: You've eaten a slice or two, and there's still more than half left.
