Control surfaces are movable parts on an aircraft's wings and tail that help manage its flight. They include ailerons, elevators, and rudders, which adjust the aircraft's orientation and direction. By changing the airflow around these surfaces, pilots can make the aircraft roll, pitch, or yaw, allowing for smooth and controlled maneuvers. These surfaces work in conjunction with the aircraft's flight control system, which can be manual or automated. When a pilot moves the control stick or yoke, it sends signals to the control surfaces, enabling precise adjustments. This interaction is crucial for maintaining stability and safety during flight.