An aquifer is a natural underground layer of water-bearing rock or sediment that can store and transmit groundwater. These formations are crucial for supplying fresh water to wells, springs, and rivers. Aquifers can be found in various geological settings and are often replenished by rainfall or surface water that seeps into the ground. There are two main types of aquifers: confined and unconfined. Confined aquifers are trapped between layers of impermeable rock, while unconfined aquifers are directly connected to the surface. Understanding aquifers is essential for managing water resources and ensuring sustainable access to fresh water for communities and ecosystems.