Subterranean water, also known as groundwater, is water that exists beneath the Earth's surface. It fills the spaces and cracks in soil, sand, and rock layers, forming aquifers. This water is crucial for drinking supplies, agriculture, and industrial uses. Groundwater is replenished through precipitation, such as rain and snow, which seeps into the ground. It can be accessed through wells and springs. The quality and quantity of subterranean water can be affected by factors like pollution, over-extraction, and climate change, making its management essential for sustainable use.