In Copernican scheme, the sun is the center of the solar system, while in the Ptolemaic system, the earth is the center of the universe and all the bodies of the universe revolve around it :)
The Ptolemaic system belived that the earth was the center of everything and all the planet and sun traveled around it and the copernican system belived that the sun was the center of everything and...
The Ptolemaic model said that the Earth was the center of the universe and the sun revolved around the Earth. The Copernican model says that the Earth revolves around the sun.