An ordinance is most commonly officiated by persons who have been ordained to an office in the priesthood acting under the direction of one who holds priesthood keys. For example, the holders of the various offices of the Aaronic Priesthood officiate in the ordinance of the sacrament under the keys and direction of the bishop, who holds the keys of the Aaronic Priesthood. The same principle applies to the priesthood ordinances in which women officiate in the temple. Though women do not hold an office in the priesthood, they perform sacred temple ordinances under the authorization of the president of the temple, who holds the keys for the ordinances of the temple.