An elastic collision is a collision in which the colliding objects bounce back after the collision without the generation of any heat or the deformation of any of the objects. On the other hand, in an inelastic collision, the shapes of the colliding objects become distorted and/or heat is generated as a consequence of the collision. In an elastic collision, total kinetic energy and the total momentum before and after the collision are the same. In an inelastic collision, some of the energy gets converted into other forms of energy such as sound energy or thermal energy.

The forces featured by an elastic collision are conservative in nature. The mechanical energy is not converted into another form of energy such as thermal energy or sound energy. The forces featured by an inelastic collision are non-conservative in nature. The mechanical energy in these collisions is transformed into a different form of energy such as thermal energy or sound energy. An example of elastic collision can be observed in the movement of swinging balls. An ideal example of an inelastic collision is the collision between two automobiles.