Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first object.  Newton’s third law is the law of action and reaction. Action force is a pair of forces that are described in Newton’s third law. Reaction forces is the force that is equal in strength and opposite in direction to the action force, which acts simultaneously on whatever is exerting the action force. This means there is a pair of forces acting on two objects. Forces always come in pair; equal and opposite action-reaction force pairs.

A force is a push or pull on an object that interacts with another object. A force never occurs by itself, but is always part of another equal and opposite force. A given force exerted on a small mass-produces a greater acceleration than the same force exerted on the large mass.

This picture is two people pushing equal forces on eachother, applying the same force.

In this picture, the boy's feet are pushing on the skateboard while the skateboard pushes up on the boy. This is a good example of Newton's third law.

In the picture, the tires are pushing downwards and backwards on the pavement, as the pavement pushes the tires upwards and forwards, therefore causing the car to move.