As Pope Benedict XVI prepares for his first visit to the U.S., some Americans may be preparing themselves by attempting to memorize his full title: 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 State of the Vatican City, Servant of the Servants of God.

Someone with such credentials must be pretty important.

For Benedict, however, it's not about importance despite his red leather papal shoes. Instead, the role of pope is one of extreme holiness.

The title of pope signifies, through centuries of Catholic doctrine, the most significant link between God and Earth. He is therefore infallible in his definition of faith and morality because of his direct -- and divine -- communication with God. His primary role is to govern the Catholic religion's policies. As leader of the church, he is based at the Vatican -- which more than 1 billion people worldwide consider their holy headquarters.

One of the pope's duties is to appoint cardinals, who form the College of Cardinals. As a body, it works to advise the pope on various religious matters. Upon a pope's death, it elects a new pope in what is called a "papal election." There are 178 cardinals worldwide, with 13 in the United States.

A cardinal may also simultaneously hold the title of archbishop. The U.S. has 45 archbishops. An archbishop is a bishop of a major or metropolitan diocese, or area of churches, such as the 5 million-member diocese of Los Angeles.

A bishop is an instructor of doctrine, a minister and a priest. He is ordained to his station just as a priest is ordained to his. The U.S. has 290 active bishops with 194 in charge of dioceses.

All of these stations in the Catholic hierarchy may perform the duties of a priest: administer sacraments such as the Holy Communion, baptism, confirmation, reconciliation, matrimony, holy orders and anointing the sick.

Contrary to popular belief, some priests may be married -- as long as they are not married after their ordination. Many rules dictate these marriages and divorce is prohibited. Only one priest has successfully divorced his wife.

Unlike a priest, a deacon cannot perform certain holy duties; he or she cannot give absolution, anoint the sick or celebrate Mass. However, a deacon may serve as a witness to a marriage, give blessings, perform baptism, preside at funerals, perform the Benediction of the Blessed Sacrament, and distribute Communion.