What is a place in desert that made fertile by steady supply of water?

An oasis is a place in a desert that is made fertile by a steady supply of water. Oases are usually formed where groundwater comes to the surface or where a river or stream flows through a desert. The water from the oasis supports plant and animal life, creating a green and lush area in the midst of the desert. Oases have been important places for human settlement and trade for centuries, and they continue to be important sources of water for people and animals in desert regions today.