The laws of motion are three fundamental principles formulated by Sir Isaac Newton that describe how objects move. The first law states that an object at rest stays at rest, and an object in motion continues in motion unless acted upon by an external force. This is often referred to as the law of inertia. The second law explains that the acceleration of an object depends on the net force acting on it and its mass, expressed in the formula F = ma, where F is force, m is mass, and a is acceleration. The third law states that for every action, there is an equal and opposite reaction, meaning forces always occur in pairs.