Immigration Law refers to national government policies which control the phenomenon of immigration to their country. Immigration law, regarding foreign citizens, is related to nationality law, which governs the legal status of people, in matters such as citizenship. Immigration laws vary from country to country, as well as according to the political climate of the times, as sentiments may sway from the widely inclusive to the deeply exclusive. Immigration law regarding the citizens of a country is regulated by international law. Immigration Law deals with issues regarding Extradition, Green Cards, Naturalization & Citizenship, Visas as well as Work Permits.