Holy See
Although the Holy See is sometimes metonymically referred to as the "Vatican", the Vatican City State was distinctively established with the Lateran Treaty (1929) between the Holy See and Italy to ensure the temporal, diplomatic, and spiritual independence of the Papacy. As such, ambassadors are officially accredited to the Holy See and not the Vatican City State. Conversely, Papal nuncios to states and international organisations are recognised as representing the Holy See and the integrity of the Catholic Church along with its 1.3 billion members, not the Vatican City State, as prescribed also in the Canon law of the Catholic Church (1983). The "Holy See" thus refers to the See of Rome viewed as the central government of the Catholic Church. The Catholic Church, in turn, is the largest non-government provider of education and health care in the world, while the diplomatic status of the Holy See facilitates the access of its vast international network of charities.
Vatican City
On 22 February 2011, Pope Benedict XVI promulgated a new "Law concerning citizenship, residency and access" to Vatican City, which became effective on 1 March. It replaced the 1929 "Law concerning citizenship and residence". There are 16 articles in the new law, whereas the old law had 33 articles. It updated the old law by incorporating changes made after 1929, such as the 1940 granting of Vatican City citizenship, "durante munere", to the members of the Holy See's diplomatic service. It also created a new category, that of official Vatican "residents", i.e., people living in Vatican City; these are not necessarily Vatican citizens.