An aileron is part of an airplane. At least it’s part of some planes. However, I can’t say for certain whether it’s a necessary part of all airplane designs. For example, I have no idea if Orville and Wilbur’s planes had them.
An aileron is a hinged surface at the back end of the plane’s wing. It’s used to control the plane’s lateral stability.
I’ve been a passenger in airplanes, but I’ve never flown one. If my life ever depends on me being able to fly a plane my life will end shortly thereafter. My moments of life will last only as long as it takes for the plane to fall from its current altitude to the altitude of the ground below, assuming the plane doesn’t break up and kill me before it makes contact with the ground.
The point I’m trying to make is that I don’t know the first thing about aeronautics. When I’m a passenger in a plane, I count on the pilot to know about how, among other important tasks, to productively use the aileron to keep the plane under control and in the air until he or she is ready to make a controlled landing, preferably at the destination listed on my ticket.
So, don’t expect any more information about ailerons from me. Sorry about that.