Evaporation:
Heat from the Sun causes water on Earth (in oceans, lakes etc) to evaporate (turn from liquid into gas) and rise into the sky. This water vapor collects in the sky in the form of clouds.
Condensation:
As water vapor in the clouds cools down it becomes water again, this process is called condensation.
Precipitation:
Water falls from the sky in the form of rain, snow, hail, or sleet, this process is called precipitation.
Collection:
Oceans and lakes collect water that has fallen. Water evaporates into the sky again and the cycle continues.