Which of the following describes an aquifer with impermeable layers above and below it?

A confined aquifer is characterized by the presence of impermeable layers both above and below it. These layers restrict the flow of groundwater, creating pressure within the aquifer. Because of this confinement, water in a confined aquifer is typically under pressure, which can lead to artesian conditions where water will flow to the surface without the need for pumping if a well is drilled into the aquifer. This contrasts with unconfined aquifers, which are directly recharged by surface water and have no impermeable layer above them, allowing water levels to fluctuate based on rainfall and surface conditions. The perched aquifer refers to a localized accumulation of groundwater above a regional water table due to an impermeable layer, while an artesian aquifer is a type of confined aquifer specifically known for its ability to produce flowing wells due to the pressure difference. Understanding these distinctions is key in hydrogeology and water resource management.