Step-by-step explanation:
Sun is the is the cause of entire water cycle because it is responsible for for its major two components that are
1. Condensation
2. Evaporation
The Sun's heat cause the evaporation( water converting into vapor) of water from the earth. This water ends up in atmosphere as water vapor. It cools and rise becoming cloud, and this eventually condenses to water droplets in form of rain or dwe.