The hydrological cycle describes the continuous movement of water on, in, and above the earth. Water is a cyclic resource that can be used and re-used, establishing a fundamental interrelationship between its various elements.

The cycle represents the circulation of water within the earth's hydrosphere in different forms. These forms include the liquid, solid, and gaseous phases, showing how water transforms but remains part of a single continuous system.

Various elements are linked through a continuous exchange of water. The cycle operates as a movement from the ocean to land and from land to ocean. This exchange connects different water bodies, ensuring water is distributed, though unevenly, across the planet.

Key processes identified as elements of this cycle include evaporation, condensation, and precipitation. For instance, evaporation results in the loss of water from the surface, while rivers input fresh water into the oceans. These processes work together to maintain the cycle.

This system has been working for billions of years, ensuring that water remains available for the existence of life. The interrelation of these elements makes the earth a 'Blue Planet' capable of supporting life.