What 2 ideas were introduced in Newton's principia?

Explanation:

Newton's first law states that a stationary body remains at rest, and a moving body remains in motion unless a resultant force acts on it, which is known as the law of inertia of bodies. Newton's second law states: If we act upon a body with a force that changes its state of motion, then this force is equal to the magnitude of the change in momentum with respect to time.