Spain is not a federation, but a highly decentralizedunitary state. While sovereignty is vested in the nation as a whole, represented in the central institutions of government, the nation has, in variable degrees, devolved power to the communities, which, in turn, exercise their right to self-government within the limits set forth in the constitution and their autonomous statutes. Each community has its own set of devolved powers; typically those communities with a stronger local nationalism have more powers; this type of devolution has been called asymmetrical. Some scholars have referred to the resulting system as a federal system in all but name, or a "federation without federalism".There are 17 autonomous communities and two autonomous cities that are collectively known as "autonomies".[i] The two autonomous cities have the right to become autonomous communities, but neither has yet exercised it. This unique framework of territorial administration is known as the "State of Autonomies".[ii]
The autonomous communities are governed according to the constitution and their own organic laws known as Statutes of Autonomy,[iii] which define the competences that they assume. Since devolution was intended to be asymmetrical in nature, the scope of competences vary for each community, but all have the same parliamentary structure.