How does an airplane fly?
When a stationary airplane is standing on the ground, the atmosphere (the same air that we breath) is pressing down on the top of wings and pressing up on the underside of the wing with the SAME pressure. The engines on the plane are used to produce forward motion and, as the plane moves forward, the wings slice, like a knife, through the atmosphere causing some air to flow over the top of the wing and some air to flow under the bottom of the wing. The shape of the wing causes the air flowing over the top of the wing to have LESS pressure than the air flowing under the wing. MORE pressure underneath pressing up and LESS pressure on the top pressing down is what lifts the plane off the ground. The greater the difference between the lower pressures on the top of the wing, and the higher pressure underneath, the faster the plane will rise.