What is Newton's third law of motion?

Newton's third law of motion states that for every action, there is an equal and opposite reaction. This principle highlights the relationship between forces; when one object exerts a force on another, the second object exerts a force of equal magnitude but in the opposite direction back on the first object. This is fundamental to understanding how objects interact in the physical world, as it emphasizes that forces always come in pairs. For example, when you push against a wall, the wall pushes back with an equal force. This law is essential in explaining various phenomena, such as propulsion in rockets and the motion of objects when they collide. Understanding this law is crucial for grasping concepts in mechanics and physics as a whole.