The Laws of Motion are three fundamental principles formulated by Sir Isaac Newton that describe the relationship between the motion of an object and the forces acting on it. The first law states that an object at rest stays at rest, and an object in motion continues in motion at a constant velocity unless acted upon by an external force. This is often referred to as the law of inertia. The second law quantifies this relationship, stating that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. The third law asserts that for every action, there is an equal and opposite reaction, meaning forces always occur in pairs.