What is the source of the water cycle?
The water cycle includes three main steps:
Evaporation: mainly from the surface of the oceans, and secondarily from the surface of other bodies of water, plus from the vegetation.
Condensation: this creates clouds.
Precipitation: this create the rain.
The main source of the water cycle is the evaporation from the oceans,
Once the rain falls some of it will flow on the land surface (runoff) other will be absorbed by the vegetation and finally some will percolate underground (infiltration) to fill the aquifers that will then originate springs feeding the rivers.
Runoff and rivers will return the water to the oceans from where it will evaporate back to the atmosphere. Vegetation will partially return the water directly to the atmosphere as water vapor during the evaporation. The cycle is completed.