Ailerons are movable surfaces located on the wings of an aircraft. They play a crucial role in controlling the aircraft's roll, which is the rotation around its longitudinal axis. When a pilot moves the control stick or yoke to one side, one aileron moves up while the other moves down, causing the aircraft to tilt in the desired direction. These surfaces are essential for maneuverability during flight, especially during turns. By adjusting the ailerons, pilots can maintain balance and stability, ensuring a smooth flight experience. Ailerons are just one part of the larger control system that includes other surfaces like elevators and rudders.