The water cycle is the continuous movement of water on, above, and below the surface of the Earth. Water changes states among liquid, vapor, and ice as it moves through the different stages of the cycle. The sun drives the water cycle, providing energy to evaporate water from the oceans, lakes, and rivers. This water vapor rises into the atmosphere, cooling and condensing into clouds. The clouds eventually release the water vapor as rain or snow, which falls to the ground. The water then either runs off into surface water bodies or seeps into the ground, where it can be stored in aquifers. The water eventually evaporates again, and the cycle begins anew.