User: What creates moon phases and how is it different from an eclipse?
Assistant: The moonlight we see on Earth is sunlight reflecting off the Moon surface. How much of the Moon we see changes day-to-day and is called lunar phases. The Moon orbits Earth and Earth orbits the Sun. Everything is moving. The phases of the moon are actually just a result of our perception of the moon's half-illuminated surface. When the moon does pass through Earth's shadow the result is a lunar eclipse.

The phases of the moon are the changes in the amount of the surface of the moon that are illuminated by the Sun from the perspective of earth. When the surface of the side of the moon facing Earth is completely illuminated, we see a full moon. When none of the surface is illuminated and we can’t see the moon at all, the phase is a new moon. When half the side of the moon facing Earth is lit up, the phases are called the first and third quarters. When the visible moon appears to be getting bigger, we say it is waxing; when the visible lighted surface seems to be getting smaller, we say the moon is waning. When less than half of the visible moon is lit, it’s called a crescent, and when it’s more than half, it’s called a gibbous.

During a lunar eclipse, Earth comes between the Sun and the Moon, blocking the sunlight falling on the Moon. Earth's shadow covers all or part of the lunar surface.