Step-by-step explanation:
Newton's third law states that when ever a force is exerted in a direction, an equal amount of force acts in the opposite direction. This is also known as action -reaction principle. The action -reaction pair does not act on the same body. The force which is exerted is known as action force and and the force which acts in the opposite direction in its response is known as reaction force.
For example, in order to walk, we push the floor backwards. This is action force. in response, the floor pushes the foot forward. This is reaction force. Action force was exerted on floor and reaction force was applied on the foot.