When something revolves, it turns on an axis or in an orbit around something else. People who love you probably think the world revolves around you (but really, the earth revolves around the sun).
Revolve comes from those useful Latin roots re- "again" or "back" and volvere "roll," as seen in evolution, involve, and lots of other familiar words. Picture a revolving door, and you can understand what it means to revolve, or turn in a circular motion.
