The water cycle essentially has no starting or ending point. The sun drives the water cycle by heating up the water from the surface of the earth such as from oceans, lakes, ponds, rivers, streams, and even ice and snow. Water then evaporates into the form of vapor. Rising air currents take the vapor up into the atmosphere where cooler temperatures cause it to condense into clouds. Air currents move the clouds around the globe. Cloud particles collide, grow, and fall out of the sky as precipitation. Some precipitation falls in the form of snow. This can accumulate as ice caps and glaciers which can store frozen water for thousands of years. The vast majority of precipitation is in the form of rain and falls back into the oceans and land.
Precipitation falling on land either runs off towards the oceans into nearby lakes, ponds, and streams or percolates into the ground replenishing underground aquifers. Some of this infiltration stays close to the land surface and can seep back into surface-water bodies (and the ocean) as ground-water discharge, and some ground water finds openings in the land surface and emerges as freshwater springs. Over time, the water continues flowing, some to reenter the ocean renewing the water cycle.