The central authority of the Catholic Church is more correctly referred to as the Holy See (the See or seat of Peter) and the central administration is the Roman Curia, most of whose offices are located within the Vatican. Some are in the City of Rome but regarded as 'extra territorial' property.
The Secretariat of State is directly responsible for a number of other offices and publications:
In 1958 the Commission for Latin America was set up to look at the particular needs of the Church in Latin America and to assist the Latin American Bishops' Conference [CELAM]. It was incorporated into the Congregation for Bishops in 1969
APSA was set up after 1870 to look after what the Holy See had left after the loss of the Papal States with the unification of Italy. Its work became more important after the 1929 Lateran Treaty with Italy, when the Vatican was compensated for the loss of territory. The monies paid in compensation were invested and form a large part of the ordinary income of the Holy See. It also looks after the ordinary financial administration of the Curia (salaries etc.)
The IOR is an office set up to gather and administer funds for religious purposes. It provides clearing-bank services for those working in the Vatican and for many religious orders, who hold a large proportion of its investments and their yields. The Holy See receives the profits it makes on its transactions.
The Prefecture of the Papal Household took its present form in the re-organization within the Vatican under Paul VI. The running of the Papal Household involves the pope's daily timetable, principally events like audiences (private and public).
Separate from the Archives is the Vatican Library. Like the Archives, it has lost most of what existed up to the XIII century but preserves many historically important manuscripts.
The Vatican Polyglot Press has its origins in the XVI century and with the Vatican Publishing House is now mainly concerned with the production and distribution of the documents of the Holy See. Vatican Radio, Vatican Television and the Vatican's own (unofficial) newspaper, L'Osservatore Romano, are all fairly recent additions to the Church's efforts to evangelise. The radio was founded in 1931 and the TV centre in 1983. The newspaper was founded in 1861 and is published every day in Italian and weekly in a number of other languages, including English.
Other sources of information regarding the Holy See are its own yearbook (Annuario Pontificio, in Italian) and the Acta Apostolicae Sedis (the official Latin text of all documents issued by the Holy See). The Statistics Office of the Secretariat of State publishes a Statistical Yearbook which gives detailed statistics for the Catholic Church worldwide. The figures are a few years out of date simply because of the time it takes to collate them.
The Vatican is on the Internet at www.vatican.va