People who have received holy orders or who have been ordained (see Seven Sacraments) are part of a union known as the clergy

Clergy

Clergy is the generic term used to describe the formal religious leadership within a given religion. A clergyman, churchman or cleric is a member of the clergy, especially one who is a priest, preacher, pastor, or other religious professional....

, a formal religious leadership within a denomination or a religion. The Catholic Clergy

Catholicism

Catholicism is a broad term for the body of the Catholic faith, its theologies and doctrines, its liturgical, ethical, spiritual, and behavioral characteristics, as well as a religious people as a whole....

, the head with the Pope

Pope

The Pope is the Bishop of Rome, a position that makes him the leader of the worldwide Catholic Church . In the Catholic Church, the Pope is regarded as the successor of Saint Peter, the Apostle...

 - being Pope Benedict XVI

Pope Benedict XVI

Benedict XVI is the 265th and current Pope, by virtue of his office of Bishop of Rome, the Sovereign of the Vatican City State and the leader of the Catholic Church as well as the other 22 sui iuris Eastern Catholic Churches in full communion with the Holy See...

.

Ranks

The altar servants assist with the services carried by the Catholic Church. The next rank then moves on to the ordained staff. The priest

Priest

A priest is a person authorized to perform the sacred rites of a religion, especially as a mediatory agent between humans and deities. They also have the authority or power to administer religious rites; in particular, rites of sacrifice to, and propitiation of, a deity or deities...

's title is Father (sometimes abbreviated as Fr.)Then a bishop

Bishop

A bishop is an ordained or consecrated member of the Christian clergy who is generally entrusted with a position of authority and oversight. Within the Catholic Church, Eastern Orthodox, Oriental Orthodox Churches, in the Assyrian Church of the East, in the Independent Catholic Churches, and in the...

 addressed as "his grace" serves Mass in a cathedral. Next is an archbishop

Archbishop

An archbishop is a bishop of higher rank, but not of higher sacramental order above that of the three orders of deacon, priest , and bishop...

, an elevated bishop whom has been ordained three times. Next, elevated from the archbishop position, a cardinal

Cardinal (Catholicism)

A cardinal is a senior ecclesiastical official, usually an ordained bishop, and ecclesiastical prince of the Catholic Church. They are collectively known as the College of Cardinals, which as a body elects a new pope. The duties of the cardinals include attending the meetings of the College and...

is formed that serves the Pope at The Vatican with Communion during Mass. Next is the Pope, the elected head of the Catholic Church.