Some asshole deleted what I wrote before, so I had to do it all over again at the last minute.
Newton's third law is the law of motion. This law is about forces. Forces are the results of interactions between objects. There are several different types of forces that can occur due to interactions between objects. These include, but are not limited to, friction forces, normal forces, tensional forces, and applied forces. When objects interact, the force that an object receives is equal to the force that that it gives. The direction of the two forces are opposite each other. "For every action, there is an equal and opposite reaction." Sounds like a threat, but it is one of the laws that governs our physical environment everyday.