* Groundwater: This refers to water that exists underground, filling spaces within rock formations and soil. It's a major source of drinking water for many communities.

* Evaporation: This is the process of water changing from a liquid to a gas (water vapor).

* Condensation: The opposite of evaporation, where water vapor changes back into liquid water, forming clouds.

* Precipitation: Water falling from the atmosphere to the Earth's surface in the form of rain, snow, sleet, or hail.

Let me know if you have any other questions!