Federalism is a political concept in which a "group" of members are bound together by covenant with a governing representative head. The term "federalism" is also used to describe a system of government in which sovereignty is constitutionally divided between a central governing authority and constituent political units, variously called states, provinces or otherwise. Federalism is a system based upon democratic principles and institutions in which the power to govern is shared between national and provincial/state governments, creating what is often called a federation. Proponents are often called federalists.