The water cycle is the continuous movement of water on, above, and below the surface of the Earth. It involves several processes, including evaporation, where water from oceans, rivers, and lakes turns into vapor and rises into the atmosphere. This vapor cools and condenses to form clouds, which eventually leads to precipitation, such as rain or snow, returning water to the ground. Once the water reaches the ground, it can flow into rivers and lakes or soak into the soil, replenishing groundwater. This water can then be taken up by plants or flow back into larger bodies of water, continuing the cycle. The sun plays a crucial role in driving this process by providing the energy needed for evaporation.