A unitary system of government is not defined by a geographic distribution of power, but rather all of the power resides in one centralized government.
In a unitary system of government, if there are any lower-level governments, they do nothing but implement the power imposed by the central government. In a unitary government, the same set of laws applies throughout the entire country or nation. Lawmakers create the policy, and then that policy is applied uniformly. A unitary government must overlook all of the local differences that may exist throughout the nation that could call for different rules or policies.