The description you provided does not accurately describe a unitary system. In a unitary system of government, the central government holds the primary power, and any administrative divisions (such as provinces or states) have only the powers that the central government chooses to delegate to them. This means that the central government is sovereign, and while it can grant certain powers to local governments, it retains the authority to revoke those powers at any time.
In contrast, the description you provided better fits a federal system, where states or provinces have significant powers and can grant some authority to the national government. In a federal system, the constitution typically delineates the powers of both levels of government.
In summary:
- Unitary system: central government holds most of the power, with limited authority delegated to local governments.
- Federal system: states hold significant powers, which can include the delegation of certain powers to a national government.