The Holy See has long been recognised as a subject of international law and as an active participant in international relations. One observer has stated that its interaction with the world has, in the period since World War II, been at its highest level ever. It is distinct from the city-state of the Vatican City, over which the Holy See has "full ownership, exclusive dominion, and sovereign authority and jurisdiction".

Vatican City, officially the Vatican City State, is a landlocked sovereign country, city-state, microstate, and enclave within Rome, Italy. It became independent from Italy in 1929 with the Lateran Treaty, and it is a distinct territory under "full ownership, exclusive dominion, and sovereign authority and jurisdiction" of the Holy See, itself a sovereign entity under international law, which maintains the city-state's temporal power and governance, diplomatic, and spiritual independence. The Vatican is also a metonym for the pope, Holy See, and Roman Curia.