To explain how lift is generated, one might consider Bernoulli’s Equation of Fluid Dynamics. The principle states that as a liquid passes over the surface of an object, it puts pressure across the surface. If the speed of the liquid must be the same on either side and the pressure on the top of an object is greater than that on the bottom, the liquid must travel faster on the top than the bottom to be equal. This causes the liquid traveling on the top to apply less pressure than the bottom.
       

        By looking at the equation, if the velocity (V) increases, the pressure (P) must decrease in order for the equation to remain constant. Because of this, the pressure on the top is less than that on the bottom resulting in the net force of the two opposing pressures to point up, as shown in the image in the bottom left.

        If you consider air as a liquid, this concept will show that as the air on top of the wing must travel faster, and slower on the bottom. It results in the net pressure on the wing to point up, causing lift.