The Vindhyas do not form a single range in the proper geological sense: the hills collectively known as the Vindhyas do not lie along an anticlinal or synclinal ridge. The Vindhya range is actually a group of discontinuous chain of mountain ridges, hill ranges, highlands and plateau escarpments. The term Vindhyas is defined by convention, and therefore, the exact definition of the Vindhya range has varied at different times in history.