Read the descriptions again. On a flying wing (delta wing) there isn't a tail, right? Therefore you need elevons to fly the plane. Elevons allow the ailerons to function as elevators when the elevator stick is moved. When Ailevators are set up on a plane with a tail and dual elevator servos, the elevators will function as ailerons in addition to the wing ailerons when the aileron stick is moved. Big difference. Ailevators are used mostly on jets with a tail for better roll control.