The shape of an aerofoil blade is designed to create lift. The lift is created by the difference in pressure between the top and bottom of the blade. The pressure is higher on the top of the blade because the air is moving faster over the top of the blade than it is over the bottom of the blade. This difference in pressure creates a force that pushes the blade up, which is lift. The shape of an aerofoil blade is called a **camber**. The camber is the difference in the thickness of the blade from the top to the bottom. The greater the camber, the more lift the blade will produce.