If we can make air speed up over a wing, the pressure of the air over the wing will drop. The higher-pressure air below the wing will then push the airplane up. Squeeze the Stream shows what happens when a fluid is forced to flow from a wide space through a narrower channel. Freely flowing water does not compress easily. Instead, it speeds up as the channel narrows.
Water also speeds up as it moves around an object, such as a rock in the river.
As you saw with the other activities, when air moves faster, its pressure drops and it pushes less. When an airplane flies, it pushes air out of the way. That air must go somewhere - so it squeezes between the wings and the surrounding air. The wings are shaped and tilted so that the air moving over the top has less room than the air moving below the wings. Because it has less room, the air moving over the top must speed up more.