The Pope is the Bishop of Rome, Vicar of Jesus Christ, Successor of the Prince of the Apostles, Supreme Pontiff of the Universal Church, Primate of Italy, Archbishop and Metropolitan of the Roman Province, Sovereign of the Vatican City State, Servant of the servants of God, and previously called the Patriarche to the West. He is the leader of Vatican City and the [Roman] Catholic branch of Christianity. There have currently been 266 Popes since the founding of the papacy. The Pope is considered infallible when speaking from ex cathedra on St. Peter's Throne, which is very, very rare.
A Pope may resign from his place in special circumstances, and once a Pope dies, he is to be replaced quickly. The election of the Pope is a long and complicated process that begins up to twenty days after the death of the previous Pope. Cardinals will discuss candidates for the next in line for the papacy, and will vote on who will become the next Pope. Anybody may be elected as a Pope, so long as they are a [Roman] Catholic male who has been Baptised and ordained. After the voting, the votes are collected in a chalice and burned. Special chemicals are used to make the smoke white or black. If white, a new Pope is elected, and if black, the votes were inconclusive and they most have a recount. After this, there is a ceremony to elect and canonize the new Pope into office.
The Pope holding the least amount of time in office was Pope Urban VII, who held office for 13 days, and the Pope holding the most amount of time in office was Pope Pius IX. The current Pope is Pope Francis I.
The papacy was founded by Jesus in 32 A.D., during his Perean-Judean ministry. He ordained St. Peter as the first Pope, the leader of the Apostles once He passes on. After Jesus dies, is raised again, and ascends up to Heaven, Peter takes the position of public speaker of the Apostles. Peter would travel up to Rome later in his life and serve as Bishop there. Because Rome was considered the center of the world at that time, the Bishop of Rome was thought to be the Apostolic sucession of Peter's special place in the Apostles. This has been called the papacy, and the sucessors of Peter have been called Popes.
The word "Pope" actually came 300 years later, but even before that the Bishop of Rome had a special place above the other bishops about the land, as shown in the First Epistle of Clement, where Pope Clement I instructs another church in what to do in an authoritive manner. The Pope is thought to unite the church as a universal church.
During the Great Schism of Roman Catholic and Eastern Orthodox faiths, the issue of the Pope came up after the major split. Eventually, the Orthodoxy rejected the Pope, though some did hold him to a high position. Protestants also rejected the Pope altogether during the Reformation.
The Pope is considered a shepherd to the [Roman] Catholic church, and is supposed to guide them in what is right, uniting them. The Pope establishes doctrine and will call ecumenical councils. The Pope also has a lead in the politics of the Vatican, serving as the leader of that place.
The Pope wears three crowns to represent Popes role as supreme priest, supreme teacher, and supreme pastor. The Pope wears a ring called the Ring of the Fisherman, which is a ring that has a picture or Peter in a boat with the name of the new Pope on it. Popes carry around a staff with a crucifix at the top, and will wear either a Rosary or a crucifix around their neck depending on the situation.
Popes will wear a falda, stole, mantum, and maniple during Mass, and casual wear is a white cassock with attached pellegrina and girded with a fringed white fascia, red papal shoes, and a white zucchetto, and may wear a red cappello romano as well.
While attending and not celebrating Mass, the Pope may wear a cassock and a rochet and mozzetta.
Popes will ride around in the Popemobile, though the latest Pope isn't fond of it.
Pope is Latin for "father."