Water cycle is the cyclic flow of water from the atmosphere to the earth and then back to the atmosphere through various processes.
Water in various water bodies gets evaporated by the heat of the sun. This evaporated water goes up in the atmosphere. The water droplets in the air condense to form clouds. When the droplets become too heavy to be held back in the clouds, they drop down as rain on the earth. This rainwater evaporates and forms clouds again. Thus, there is a cyclic flow of water between the atmosphere and the earth; it is termed as the water cycle.