What is the hydrological cycle and its main components?

The hydrological cycle describes continuous movement of water between Earth's surface and atmosphere. Main components: precipitation (rain, snow) reaches Earth's surface, some water becomes runoff flowing to streams and oceans, some infiltrates into soil becoming groundwater, plants absorb water releasing it through transpiration, and water evaporates from surfaces. Combined evaporation and transpiration is called evapotranspiration. This cycle maintains water balance and drives all water resources engineering.