Federalism is a type of government in which the power is divided between the national government and other governmental units. It contrasts with a unitary government, in which a central authority holds the power, and a confederation, in which states, for example, are clearly dominant.
Federalism is the theory or advocacy of federal principles for dividing powers between member units and common institutions. Unlike in a unitary state, sovereignty in federal political orders is non-centralized, often constitutionally, between at least two levels so that units at each level have final authority and can be self governing in some issue area. Citizens thus have political obligations to, or have their rights secured by, two authorities.
The division of power between the member unit and center may vary, typically the center has powers regarding defense and foreign policy, but member units may also have international roles. The decision-making bodies of member units may also participate in central decision-making bodies.