Force is the product of mass times acceleration or more classically defined it is the force that when acting on unit mass produces unit acceleration. In the CGS system it is termed the dyne and in the FPS the poundal. Both units are absolute and invariable. In engineering, however, the unit of force is found more convenient to be the weight of a one-pound mass. Pound Weight is termed a gravitational unit. It follows that, as the force due to gravity changes from place to place, so does magnitude of the pound weight (the force of one-pound weight will be greater at the poles than at the equator).
From the units of force are derived other units such as work (joule, foot-poundal) and power (watt). The corresponding gravitational units would be foot-pound and horsepower. In physics and physical chemistry measurements absolute units are preferred and almost exclusively used.