Animation from http://commons.wikimedia.org.

The moon goes through different phases as it rotates around the earth. The moon itself does not change, but the light reflected from it does change.

Here are the phases:

Full moon - the sun's light reflects fully from the moon. There is no shadow on the moon.

Waxing gibbous - the earth blocks just a little of the sun's light. It looks kind of like a fingernail.

First quarter - One half of the sun's light is blocked, so one half of the moon is in shadow.

Picture by Manashi.

Waxing crescent - the earth blocks most of the sun's light, so only a little sliver of the moon can be seen.

New moon - the earth blocks all of the sun's light, so you can barely see the moon, if you can see it at all.

Waning crescent - the earth blocks most of the sun's light, so only a little sliver of the moon can be seen.

Third quarter - the earth blocks half of the sun's light. You can see one half of the moon.

Waning gibbous - the earth blocks only a little of the sun's light. The moon has only a little sliver of shadow on it.

To learn more about the phases of the moon, visit this site: http://www.harcourtschool.com/activity/moon_phases/.

Images from http://commons.wikimedia.org.