In the ptolemaic system, planets orbited in small circles called epicycles while revolving along large circles called deferents. Ptolemaic system or the geocentric model is a suspended description of the universe with the earth at the center, such that the sun, moon, stars and planets all orbited Earth. This model accounted for the apparent motions of the planets in a very direct way, by assuming that each planet moved on a small sphere or circle, called epicycle, that moved on a larger sphere or circle called deferent.
