In a federal system, the central (or federal) government has much more authority than in a confederal system. The central government controls more trade policy, and makes decisions about policy areas that involve interactions between states (such as highway systems).
Nationality is a legal relationship between an individual person and a state. Nationality affords the state jurisdiction over the person and affords the person the protection of the state. What these rights and duties are vary from state to state.
Definition of citizen for English Language Learners. : 1  a person who legally belongs to a country and has the rights and protection of that country. : 2  a person who lives in a particular place.