The sacrament of Holy Orders is the continuation of the mission and authority that Jesus Christ entrusted to his apostles (CCC 1575). Along with the sacrament of Matrimony, Holy Orders is directed toward the salvation of others through service, as it confers a particular mission within the Church intended to build up the People of God.

This sacrament consists of three degrees, which are conferred by validly ordained bishops (CCC 1576). These bishops possess the authority to administer the sacrament because they exist within the line of apostolic succession (CCC 1576).

The ordained ministry, or ministerial priesthood, exists to serve the baptismal priesthood, which is the calling of every baptized person to be a blessing and to bless others (CCC 1669). The theological significance of this relationship is that the ministerial priesthood guarantees that it is Christ himself who acts in the sacraments through the Holy Spirit for the benefit of the Church.

The authority granted through Holy Orders has specific implications for the administration of the sacraments. For example, only priests, comprising both bishops and presbyters, are authorized to administer the sacrament of the Anointing of the Sick (CCC 1516).