The Vatican is a city-state located in the heart of Rome, Italy, and is the smallest state in Europe, with a total area of 0.44 km² and a population of around 800-900 people. It is the center of authority over the Roman Catholic Church and is ruled by the Pope, who is the Bishop of Rome. The Vatican is also a metonym for the Holy See, which is the central governing body of the Catholic Church and a sovereign entity recognized by international law, consisting of the Pope and the Roman Curia.

The Vatican contains religious and cultural sites such as St. Peters Basilica, the Sistine Chapel, the Vatican Apostolic Library, and the Vatican Museums. It is one of the most sacred places in Christendom and stands as a testimony to a history of about two millennia and to a formidable spiritual venture. The Vatican is also an important archaeological site of the Roman world and one of the major cultural reference points of both Christians and non-Christians.

The Vatican City was declared independent from the rest of Italy on February 11, 1929, with the signing of the Lateran Treaty between Pope Pius XI and Mussolini. The Vatican City is not a democracy and is not a member of the United Nations or the European Union, although the official currency is the Euro.

In summary, the Vatican is a city-state located in Rome, Italy, and is the center of authority over the Roman Catholic Church. It is also a metonym for the Holy See, which is the central governing body of the Catholic Church and a sovereign entity recognized by international law. The Vatican contains religious and cultural sites and is one of the most sacred places in Christendom. It is not a democracy and is not a member of the United Nations or the European Union, although the official currency is the Euro.