The moon doesn't produce its own light. It shines because it reflects sunlight. The reason we see different phases of the moon is due to the changing angle of sunlight hitting the moon as it orbits Earth.

Here's a breakdown:

* New Moon: The moon is between the Earth and the Sun, so the sunlit side of the moon faces away from us. We see the moon as dark.

* Waxing Crescent: As the moon moves, a sliver of the sunlit side starts facing us, appearing as a thin crescent.

* First Quarter: Half of the moon is illuminated by the sun. It appears as a half-circle.

* Waxing Gibbous: More than half of the moon is illuminated. It appears as a rounded shape.

* Full Moon: The moon is directly opposite the Sun, with the entire sunlit side facing us. This is when we see the full moon.

* Waning Gibbous: The amount of illuminated moon starts to decrease.

* Last Quarter: Again, half the moon is illuminated, but now it's the opposite side from the first quarter.

* Waning Crescent: The sunlit side of the moon continues to shrink until we see a thin crescent again.

So, it's not that the moon is "dark" and then "bright" again, but rather the amount of sunlight reflecting off its surface that we see changes with its position relative to the Sun and Earth.