Drag
From FlightSim
Drag is resistance to forward motion, usually caused by air, though mud, grass, etc. also provide drag.
In the air, drag is generally in one of two forms: parasite drag or induced drag.
Parasite drag comes from most anything hanging out in the breeze, such as struts, antennas, wings, etc., even the fuselage and empennage. Induced drag is caused by the generation of lift, typically thought of as being on the wings, but also the horizontal tail surfaces, propeller and even the fuselage generate some degree of lift (downward in the case of the tail surfaces), and therefore they also generate induced drag.
See also the drag (physics) page on Wikipedia.
