Which law validates the statement that ‘All the planets move around the sun in an elliptical orbit, with the sun being at rest at one focus of the orbit’?

Three laws devised by Johannes Kepler to define the mechanics of planetary motion. The first law states that planets move in an elliptical orbit, with the Sun being one focus of the ellipse. This law identifies that the distance between the Sun and Earth is constantly changing as the Earth goes around its orbit.