Wind resistance is overall drag on a body due to its interaction with the atmosphere. The term is actually quite vague, and is often applied to a number of different types of drag, but since the overall effect is often most important, the term is widely used.

The power required to overcome drag due to any fluid varies with the cube of velocity, meaning that it grows rapidly with increasing speed. This is why a car may need only 25 horsepower (20 kW) in order to cruise at highway speeds, while requiring perhaps 200 horsepower (160 kW), eight times as much, to travel twice that fast. The effect is even more pronounced in aircraft, where efforts to reduce the drag coefficient become vitally important, as increasing engine power also increases the weight of the aircraft and thus the induced drag.