Known worldwide and to Catholics as the pope, the bishop of Rome is the supreme and visible head of the Catholic Church. The pope has a slew of other titles, but the most common and best-known ones are pope, Holy Father, and Roman Pontiff.
The pope’s jobs
The pope has two big jobs:
He’s the bishop of Rome, which means he has supreme, full, immediate, and universal jurisdiction all over the world (although the title says “Rome,” the job encompasses the whole Church).
He’s the head of the entire Catholic Church. As head of the Church, the pope directs the faithful around the world both directly and through mandates to the bishops who oversee the administrative territories known as dioceses. He also elevates bishops to the rank of cardinal as he sees fit.
When the pope teaches a doctrine on faith or morals to the universal Church in his unique office as supreme head, he is held to be infallible, incapable of error. When the pope asserts his official authority in matters of faith and morals to the whole church, Catholics believe the Holy Spirit guards him from error.
How the pope gets his job
The pope becomes pope through an election in the College of Cardinals. Nope, that’s not a university where priests and bishops learn how to become cardinals. The College of Cardinals refers to all the cardinals around the world, just as the College of Bishops is a way of describing all the world’s Catholic bishops.
Cardinals are bishops handpicked by the pope to become cardinals, when their primary function becomes electing a new pope when the old pope dies or resigns. Elevating cardinals is like the U.S. president nominating members of the Supreme Court — a way to ensure that the pope's political views and policies are carried on when he is no longer pope.
A two-thirds majority decision is needed to elect a new pope. If no one receives two-thirds of the votes or if the nominee declines the nomination, then wet straw is mixed with the paper ballots and burned in the chimney. The wet straw makes black smoke, which alerts the crowds gathered outside that there’s no papal successor yet. When someone receives two-thirds of the votes and he accepts the papacy, the ballots are burned without the straw, which blows white smoke to alert the crowds.
The cardinals cast votes twice a day, every day for 21 elections. If no one is elected by a two-thirds majority, then on the 22nd ballot, the man who receives a simple majority (50 percent plus one) is elected pope.
The limit of electors is set at 120, but at one point Pope John Paul II (who was pope from 1978 to 2005) had appointed so many that the number of eligible voters reached 137. With retirements and deaths, only 117 eligible voting cardinals remained when Pope John Paul II died in 2005.
Popes are elected for life unless they voluntarily — without pressure or coercion — resign from office. Pope Benedict XVI resigned in early 2013. The last pope to quit was Pope Gregory XII in 1415.) No person or body can remove a pope from office even if he becomes insane, sick, or corrupt.
The electors can vote for any other cardinal or any Catholic bishop, priest, deacon, or layman, anywhere in the world and of any liturgical rite, such as Latin, Byzantine, and so on. Normally, the cardinals select another cardinal, both because they know each other better and because the number of cardinals to choose from is small compared to the 5,000 bishops around the world and more than 410,000 priests.
Although extremely rare, if a layman is elected pope (as in the case of Benedict IX), he first has to be ordained a deacon, then a priest, and then a bishop before he can function as pope, because the authority resides in his office as bishop of Rome. If a priest is chosen, he needs to be ordained a bishop prior to being installed as pope.