* Sunlight Reflection: The Moon's surface is covered in a dusty, gray material called regolith. This regolith is very good at reflecting sunlight. When sunlight hits the Moon, a portion of it bounces back towards Earth.
* Angle of Reflection: The amount of light we see from the Moon depends on the angle at which sunlight hits it. When the Moon is full, the Sun is directly behind it, and we see the entire illuminated face. As the Moon goes through its phases, the angle changes, and we see less of the illuminated surface.
* Distance: The Moon is relatively close to Earth, so even though it only reflects sunlight, it appears bright compared to stars, which are much farther away.
In short, the Moon appears bright in the sky because it's reflecting sunlight towards Earth. The brightness we see depends on the angle of sunlight and the portion of the Moon's surface illuminated.
