The hierarchy of the Catholic Church consists of its bishops, priests, and deacons. In the ecclesiological sense of the term, "hierarchy" strictly means the "holy ordering" of the Church, the Body of Christ, so to respect the diversity of gifts and ministries necessary for genuine unity. In canonical and general usage, it refers to those who exercise authority within a Christian church. In the Catholic Church, authority rests chiefly with the bishops, while priests and deacons serve as their assistants, co-workers or helpers. Accordingly, "hierarchy of the Catholic Church" is also used to refer to the bishops alone. The term "pope" was still used loosely until the sixth century, being at times assumed by other bishops. The term "hierarchy" became popular only in the sixth century, due to the writings of Pseudo-Dionysius. As of 31 December 2020, the Catholic Church consisted of 2,903 dioceses or equivalent jurisdictions, each overseen by a bishop. Dioceses are divided into individual communities called parishes, each staffed by one or more priests, deacons, or lay ecclesial ministers. Ordinarily, care of a parish is entrusted to a priest, though there are exceptions. Approximately 22% of all parishes do not have a resident pastor, and 3,485 parishes worldwide are entrusted to a deacon or lay ecclesial minister. All clergy, including deacons, priests, and bishops, may preach, teach, baptize, witness marriages, and conduct funeral liturgies. Only priests and bishops can celebrate the sacraments of the Eucharist (though others may be ministers of Holy Communion), Penance (Reconciliation, Confession), Confirmation (priests may administer this sacrament with prior ecclesiastical approval), and Anointing of the Sick. Only bishops can administer the sacrament of Holy Orders, by which men are ordained as bishops, priests or deacons. Bishop The bishops, who possess the fullness of orders, and therefore the fullness of both priesthood and diaconate, are as a body (the College of Bishops) considered the successors of the Apostles and are "constituted Pastors in the Church, to be the teachers of doctrine, the priests of sacred worship and the ministers of governance" and "represent the Church." In 2012, there were 5,133 Catholic bishops; at the end of 2014, there were 5,237 Catholic bishops. The Pope himself is a bishop (the bishop of Rome) and traditionally uses the title "Venerable Brother" when writing formally to another bishop. The typical role of a bishop is to provide pastoral governance for a diocese. Bishops who fulfill this