The water cycle represents the circulation and recycling of water in nature. Liquid water on the planet surface is heated by the sun and turns into water vapor that gains the atmosphere. In the atmosphere large volumes of water vapor form clouds that when cooled precipitate liquid water as rain.
Therefore water comes back to the planet surface and the cycle is completed. As possible steps of the cycle, water may still be stored in subterranean reserves or in the form of ice in mountains and oceans and it may also be used in the metabolism of living beings, incorporated into the body of the individuals or excreted through urine, feces and transpiration.