That's exactly right! The phases of the moon we see are entirely determined by how much of the sunlit side of the moon faces Earth.

Here's a breakdown:

* New Moon: The moon is between the Earth and the Sun, so the sunlit side faces away from us, making it invisible.

* Waxing Crescent: A sliver of the sunlit side begins to become visible as the moon moves away from the Sun.

* First Quarter: Half of the sunlit side faces Earth, appearing as a half-circle.

* Waxing Gibbous: More than half of the sunlit side is visible, becoming rounder.

* Full Moon: The entire sunlit side of the moon faces Earth, making it appear fully illuminated.

* Waning Gibbous: The illuminated portion starts shrinking, becoming less round.

* Last Quarter: Again, half of the sunlit side faces Earth, but this time the other half compared to the First Quarter.

* Waning Crescent: The sliver of the sunlit side gets smaller and smaller until it disappears again at the New Moon.

The cycle repeats every roughly 29.5 days, giving us our familiar lunar phases.