What term describes a form of government where both national and regional entities operate together?

The term that describes a form of government where both national and regional entities operate together is federalism.

Federalism is characterized by a division of powers between a central authority and smaller political units, such as states or provinces. In a federal system, the national government has certain powers that are defined by the constitution, while regional governments retain their own powers and authority over local matters. This allows for both levels of government to coexist and operate collaboratively, each responsible for various issues, thereby enabling a balance of power and local autonomy within the larger national framework.

In contrast, a confederation typically refers to a union of sovereign states that delegate certain powers to a central authority while retaining most of their independence, which differs from the more integrated approach of federalism. Monarchy describes a government led by a single ruler, such as a king or queen, and does not involve the layered structure seen in federal systems. Democracy is a broader term that refers to a system of government in which the people exercise power, often through elected representatives, but does not specifically indicate a structure that includes both national and regional entities working together.