At the rear of the wings and stabilizers are small moving sections that are attached to the fixed sections by hinges. In the figure, these moving sections are colored brown. Changing the rear portion of a wing will change the amount of force that the wing produces. The ability to change forces gives us a means of controlling and maneuvering the airplane. Most airliners can also be rolled from side to side by using the spoilers.
Spoilers are small plates that are used to disrupt the flow over the wing.
The wings have additional hinged, rear sections near the body that are called flaps. Flaps are used on takeoff and landing to increase the amount of force produced by the wing. Slats are used at takeoff and landing to produce additional force. The spoilers are also used during landing to slow the plane down and to counteract the flaps when the aircraft is on the ground. The next time you fly on an airplane, notice how the wing shape changes during takeoff and landing.