As we have seen, before Newton and Galileo, it was accepted that the laws that governed heavenly bodies were different from the laws that governed motion on earth. That is, we see that the force between the two bodies is a function of the mass of each object and the distance between them. The law says that an object is attracted to earth by a constant force depending only on mass and distance.
Planets move in elliptical orbits.
With the law of gravity, Newton could explain how bodies stay in orbits. If a person throws a ball, it follows a curved path as gravity pulls it down, etc.