Centrifugal force () is the apparent force that draws a rotating body away from the center of rotation. It is caused by the inertia of the body. In Newtonian mechanics, the term centrifugal force is used to refer to one of two distinct concepts: an inertial force (also called a "fictitious" force) observed in a non-inertial reference frame, and also sometimes to the equal and opposite reaction to a centripetal force in any reference frame (as per Newton's third law of motion). The concept of centrifugal force is applied in rotating devices such as centrifuges, centrifugal pumps, centrifugal governors, centrifugal clutches, etc., as well as in centrifugal railways, planetary orbits, banked curves, etc. Some aspects of these situations can be analyzed in terms of the fictitious force in the rotating coordinate system, while other aspects additionally require the involvement of the reactive centrifugal force, otherwise called a normal reaction.