Forces can be categorized as conservative and non-conservative forces. Gravitational, electrostatic, and elastic restoring forces are a few examples of conservative forces. For example, a car at rest possesses potential energy while its kinetic energy is zero. When the car starts moving, its potential energy is converted to kinetic energy, and when it stops, its kinetic energy converts back to potential energy provided there is no friction. As these energies are interconverting from one form to another, the sum of kinetic and potential energy remains the same throughout the path. This interconversion of energies is governed by conservative forces. The work done by the conservative forces is consistently reversible and does not depend on the path taken by the object. It depends only on the start and the end points, and can be expressed as the difference in the potential energies at these points. However, for a closed path, the work done will be zero.