Conservative Forces:

If the work of a force in moving a particle among two positions is independent of the path followed by the particle and may be expressed as a change in its potential energy, then such force is called as a conservative force. The force that the engineer encounters most often, is the weight of the body by virtue of earth's gravitational force on the body, this is independent on the path traced by this body. Because of this property of the force, the gravitational force-field is said to be a Conservative force field and the gravity force is termed as a Conservative force. The proof that "Gravitational field is conservative" is described below.