Though no orbit is perfectly circular, the general name for any orbit that is not highly elliptical (egg-shaped) is circular. Circular orbits have an eccentricity of 0. There are several types of circular orbits and they include:
The orbital path of satellites in these circular orbits is also affected by the satellite's altitude - its height above the Earth. Satellites in geostationary orbit are always in a high orbit. If the satellite is in a polar, sun-synchronous, or equatorial orbit, its orbital altitude may be medium or it may be low. Since the altitude determines the speed of the orbit, the time it takes a satellite to complete one orbit, and the clarity with which the satellite can see the Earth, there are advantages to each type of orbit and each orbital height.