Catholics believe that through Baptism all the members of the church share in the priesthood of Jesus Christ. This is called the "common priesthood of the faithful."
Catholics also believe that the Sacrament of Holy Orders confers another kind of participation in Christ's priesthood, the ministerial priesthood of bishop and priest. This differs in essence from the common priesthood because it confers a sacred power for the service of the faithful. The ordained ministry occurs in three degrees or orders: deacon, priest and bishop.
Bishops are the chief teachers, sanctifiers and shepherds in their dioceses. Priests form a presbyteral community with the bishop and assume with him the pastoral mission for a particular parish. Deacons receive the Sacrament of Holy Orders but not the ministerial priesthood.
Only men may be ordained. Normally ordination to priesthood is only conferred on those men who freely promise lifelong celibacy.
The essential rite of the Sacrament of Holy Orders for all three degrees consists in the bishop's imposition of hands and the bishop's prayer of consecration.