In other words, they overcome the force of gravity and are kept in the air by the force of the wind or the forces of wind pressure on the kite. The aerodynamic force involved is called lift. Lift on a kite is perpendicular to the relative wind direction. It is the actual wind, the actual direction of wind and speed of the wind. The kite reacts to the wind pushing on it.
Lift is executed in an upward direction thereby opposing the pull of gravity on the kite.
There are two principles involved in the aerodynamics of kite flight. One is Newton's Law of action and reaction. Think of the kite as flying on an inclined plane and flying in one spot. The kite exerts a downward force upon the air. The air passes over the top edge of the kite and goes down the upper surface of the kite.