An airfoil shape refers to the cross-sectional design of a wing or blade that helps generate lift when moving through air. The upper surface is typically curved, while the lower surface is flatter. This design allows air to travel faster over the top, creating lower pressure above the airfoil and higher pressure below, resulting in lift. Airfoils are essential in various applications, including aircraft wings, helicopter blades, and wind turbine blades. The specific shape and angle of an airfoil can significantly affect its performance, influencing factors like lift, drag, and overall efficiency in flight or energy generation.