The water cycle is a biogeochemical cycle in which water moves continuously on, above and below the surface of the earth, including from the atmosphere to the surface, from rivers to the oceans, and from the oceans to the atmosphere, through precipitation, surface and subsurface flowing, infiltration, evaporation, and condensation.
The evaporative phase purifies water which then replenishes the land and its water bodies through precipitation with fresh water. The flow of liquid water and of ice transports minerals and helps reshape geological features through erosion and sedimentation.
The water cycle also involves the exchange of energy, resulting in cooling when water evaporates and warming when it condenses, thereby playing a major role in weather and the climate. As with the other biogeochemical cycles, the water cycle is essential for the maintenance of most life and ecosystems.