Citation:
Federalism is a system of government where power is divided between a central authority and regional or state governments. Each level of government has its own set of powers and responsibilities.
Devolution is the transfer of power from a central government to regional or local governments.
A unitary system is a form of government where power resides in a centralized authority with little or no autonomy for subnational units.
Confederation: A confederation is an alliance or union of independent states that come together for common purposes while retaining their sovereignty.