On Earth, water can be found in three main forms: liquid water, ice, and water vapor. Liquid water is the most common form of water on Earth and can be found in oceans, lakes, rivers, and other bodies of water. Ice is found in glaciers, ice sheets, and permafrost. Water vapor is the gas form of water and can be found in the atmosphere.

On the moon, water has been detected in the form of ice. This ice is located in craters near the moon's poles, where it is protected from the sun's heat. The ice on the moon is thought to come from comets and asteroids that have impacted the moon over time.