The upward force acting upon a falling object is called air resistance, according to Georgia State University. Often referred to as drag in aerodynamics, air resistance works in the opposite direction from which an object is moving.
Air resistance affects all objects moving through the air in all directions. When an object's motion is propelled by gravity or another constant force, the object reaches a terminal velocity, which is the maximum speed it can attain, since the forward force can't overcome the air resistance. In aerodynamics drag, thrust, lift and gravity are the four forces acting upon a flying aircraft, and the more lift an aircraft produces, the more drag it creates at the same time.