What scientific principle encompasses the idea that every action has an equal and opposite reaction?

The principle that states every action has an equal and opposite reaction is fundamentally encapsulated in Newton's Third Law of Motion. This law explains that when one object exerts a force on a second object, the second object exerts a force of equal magnitude but in the opposite direction back on the first object. This relationship between forces is crucial for understanding motion and interactions in physics. For example, when you push against a wall, the wall pushes back with an equal force, which is why you don't move through it. This reciprocal nature of forces is a foundational concept in mechanics, influencing countless practical applications in everyday life, engineering, and various scientific disciplines.