Energy is a measure of how long we can sustain
the output of power, or how much work we can do. There are two kinds of energy:
potential and kinetic.
Potential energy is waiting to be converted into power. Gasoline in a
fuel tank as an example.
Kinetic energy is energy a body possesses
because it is in motion.
Work is the application of a force over a
distance. Work is equal to the product of the force and the distance through
which it produces movement.