Foot-Pound refers to a measurement of work or energy. One foot-pound (ft-lb) is equal to the work done when a force of one pound is exerted on a body that moves a distance of one foot in the direction of the force.
The foot-pound is often used as a unit of torque, for example, the tightness of a fastener such as screws and nuts or the output of an engine. Although they are dimensionally equivalent. energy, (scalar), and torque are distinct physical quantities. Both energy and torque can be expressed as a product of a force vector with a displacement vector hence pound and feet, energy is the scalar product of the two, and torque is the vector product. Although referring to the torque as a unit pound-feet has been suggested, both are still commonly called foot-pound in colloquial usage. To avoid confusion, it is not common for people to specify each as foot pound energy.