The sun plays an essential role in the water cycle as it provides the necessary energy for processes like evaporation and transpiration. Through evaporation, water from oceans, lakes, and rivers transforms into vapor, while plants contribute by releasing water vapor during transpiration. This vapor rises and cools, leading to condensation and eventually forming clouds. Subsequently, water returns to Earth as precipitation. The sun's energy drives these processes, ensuring a continuous cycle that is vital for climate regulation and supporting life on Earth.