Federalism which promotes ideally non-centralization of power and believed as a multi-level governance , promotes democracy, combining unity and diversity, preserving distinct identities within a larger political union by enhancing freedom, democracy, and accomodating territorially based religious, linguistic, ethnic identities within nation state.
At present ,there are 25 federations out of 193(194? )politically sovereign states ,containing about 40 percent of world's population.