How does the water cycle work?
Water molecules are heated by the sun and turn into water vapor that rises into the air through a process called evaporation. Next, the water vapor cools and forms clouds, through condensation. Over time, the clouds become heavy because those cooled water particles have turned into water droplets. When the clouds become extremely heavy with water droplets, the water falls back to earth through precipitation (rain, snow, sleet, hail, etc). The process continues in a cyclical manner.
Learn more about Earth's water cycle on the Precipitation Education website.