Moveable surfaces on an airplane’s wings and tail allow a pilot to maneuver an airplane and control its attitude or orientation. These control surfaces work on the same principle as lift on a wing. They create a difference in air pressure to produce a force on the airplane in a desired direction.
Airplane control systems are carefully designed to provide a natural feel, and at the same time, allow adequate responsiveness to control inputs. At low airspeeds, the controls usually feel soft and sluggish, and the airplane responds slowly to control applications. At high speeds, the controls feel firm and the response is more rapid.
Incidentally, a controllable function of any rc model is referred to as a channel. An rc airplane with control to, say, four functions will be called a 4 channel plane, sometimes abbreviated to just 4 ch..