Energy is a property of objects that allows them to do work. Work is the transfer of energy from one object to another. Energy can take many forms, such as kinetic energy (energy of motion), potential energy (stored energy), thermal energy (heat), and electrical energy.

The amount of work done on an object depends on the force applied and the distance over which the force is applied. Work is measured in units of joules, and energy is measured in units of joules or calories.