Gravity is one of the 4 fundamental forces of the Universe. Gravity is the weakest of the 4 fundamental forces of the Universe. Gravity is always attractive never repulsive.
Gravity operates over long, long distances.
Play around with the eccentricity of the orbit and the masses of the bodies. As you view the animations, note that it appears we are looking up from below the Earth-satellite system. Orbits of planets are ellipses, with the Sun at one focal point. The planets sweep out equal areas in equal time. The square of the period of the planet is proportional to the cube of its distance from the Sun.