The word cycle comes from Greek word that means circle. A cycle is a series of steps that lead back to a starting point.
The water cycle describes the existence and movement of water on, in, and above the Earth. Earth's water is always in movement and is always changing states, from liquid to vapor to ice and back again. The water cycle has been working billions of years and all life Earth depends on it, continuing to work the Earth would be a pretty stale place to live without it.
The main parts of the water cycle are:
Evaporation
Condensation
Precipitation
Collection