The energy possessed by a virtue of its position or molecular arrangement(configuration) is called potential energy.
The potential energy is of the following three types:
Gravitational Potential Energy
Consider a body having mass ‘m’ is lying on the surface of the earth and ‘g’ be the value of acceleration due to gravity at that place. A force ‘mg’ is required to lift the body in upward direction. Let the body is lifted to a height ‘h’. Then work done (W) is,
W = Force x displacement
Or, W = F x h = mg x h
Or, W = mgh
This work done is stored in the body in the form of gravitational potential energy. Therefore , Gravitational potential energy = mgh .