An Artesian Basin is a geologic layer that receives water from rainfall which then seeps down and gets trapped between layers of soil, rock, or clay. Synonyms for Artesian Basin include confined aquifer, groundwater basin, and water-table aquifer. A confined aquifer or artesian well is where an impermeable layer of rock or soil lies above the water level. A groundwater basin is an area where the water table is at a similar elevation. A water-table aquifer refers to underground water systems where the permeable material lies above the impermeable material. All of these synonyms are used interchangeably when referring to underground water systems that are formed by natural geological processes.