Newton's laws consist of three fundamental principles that describe the relationship between the motion of an object and the forces acting on it. The first law, also known as the law of inertia, states that an object at rest will remain at rest, and an object in motion will continue in motion at a constant velocity unless acted upon by an external force. The second law establishes that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass, expressed as F = ma. The third law states that for every action, there is an equal and opposite reaction, meaning forces always occur in pairs.