The water cycle describes the movement of water throughout Earth's surface, atmosphere, and underground. Water is constantly moving from one place to another through the processes of evaporation, precipitation, transpiration, condensation, and runoff. Water in the water cycle can exist as a solid, liquid, or gas. The water cycle is very important to life on Earth.

Water Cycle

the cycle of processes by which water circulates between the earth's oceans, atmosphere, and land, involving precipitation as rain and snow, drainage in streams and rivers, and return to the atmosphere by evaporation and transpiration.