What is a plane wing flap called?

A plane wing flap is commonly referred to simply as a "flap." Flaps are movable surfaces on the wings of an aircraft that can be extended or retracted to increase lift during takeoff and landing. They help improve the aircraft's aerodynamic performance at lower speeds. Different types of flaps include plain flaps, split flaps, and Fowler flaps, each designed for specific aerodynamic advantages.