In astronomy, the term revolution is most often used to describe the movement of large masses around the center of mass of a system, for example the movement of a moon around a planet or a planet around a star. These orbital revolutions were first described using elliptical orbits by Kepler. Newton later was able to provide a physical model for this motion, now understood to be due to the force of gravity. Our current understanding of gravitation, and therefore of orbital revolution, also owes a great deal to the Theory of relativity developed by Albert Einstein.
Revolution in the physical sense should not be confused with revolution in the sense of political change, although the roots of the terms may be similar.