Catholicism
Many people use the word Catholicism to talk about religious beliefs of the Catholic Church, whose leader is called the "Bishop of Rome" and often called the "Pope". The Catholic Church is based in the Vatican City, a small independent country in the city of Rome, Italy. Sometimes the word also refers to beliefs of other Christian churches, including the Eastern Orthodox Churches, who have many beliefs similar to the Catholic Church, but do not believe the Bishop of Rome is their leader.