Political units are defined areas governed by a specific authority, which can include countries, states, provinces, or municipalities. These units have established boundaries and are responsible for creating and enforcing laws, collecting taxes, and providing services to their residents. The size and power of a political unit can vary significantly, from small towns to large nations like United States or China. Political units can also be categorized based on their governance structure. For example, a federal system divides power between a central government and smaller political units, while a unitary system centralizes authority. Understanding these units helps clarify how political decisions are made and how they affect citizens' lives.