It is many things which causes and airplane to fly. Partly it is the angle where the wing is set against the wind which flows over it, and partly it is the shape of the wing which makes the air on the top flow quicker then underneath. The faster flowing air creates and underpressure and the pressure under the wing forces it up in the air. The wing generates "lift" as it is said. Below there is an American eduactional film which explains about all aspects of flying an airplain in a controlled manner in the air:
If you want to learn more about how planes are flying or how to operate them, click the techincal articles to the left and read more. Not all of them are translated into English yet, but quite a few are already, and more will come.
Below are the menus translated:
Flyteori : Theory of flight (translated) Flykontroller: Flight controls (translated) Å fly flyet: To fly the aircraft Instrumenter: Instruments (translated) Normallanding: Normal landings (translated) Halehjulslanding: Tailwheel landings Landingsrunder: Landing circuits Landingi sidevind: Crosswind landings (translated) Sakteflyging: Slow flying Steiling, Flikk og Spinn: Stall, Wingdrop and Spin Spiralstup: Spiraldive Flightcomputer 1: Flight computer wind side Flightcomputer 2: Flight computer calculus side Navigasjon: Navigation Radiotelefoni: Use of radio in an aircraft