Youcat commented through CCC – Question n. 248.

YOUCAT Question n. 248 - What are the names of the sacraments that serve to build up communion in the Church?

(Youcat answer) Someone who is baptized and confirmed can receive moreover a special mission in the Church in two special sacraments and thus be enlisted in the service of God: Holy Orders and Matrimony.

A deepening through CCC

(CCC 1533) Baptism, Confirmation, and Eucharist are sacraments of Christian initiation. They ground the common vocation of all Christ's disciples, a vocation to holiness and to the mission of evangelizing the world. They confer the graces needed for the life according to the Spirit during this life as pilgrims on the march towards the homeland. (CCC 1534) Two other sacraments, Holy Orders and Matrimony, are directed towards the salvation of others; if they contribute as well to personal salvation, it is through service to others that they do so. They confer a particular mission in the Church and serve to build up the People of God.

Reflecting and meditating 

(Youcat comment) The two Sacraments have something in common: They are directed to the good of others. No one is ordained just for himself, and no one enters the married state merely for his own sake. The sacrament of Holy Orders and the sacrament of Matrimony are supposed to build up the People of God; in other words, they are a channel through which God pours out love into the world.

(CCC Comment)

(CCC 1535) Through these sacraments those already consecrated by Baptism and Confirmation (Cf. LG 10) for the common priesthood of all the faithful can receive particular consecrations. Those who receive the sacrament of Holy Orders are consecrated in Christ's name "to feed the Church by the word and grace of God" (LG 11 § 2).  On their part, "Christian spouses are fortified and, as it were, consecrated for the duties and dignity of their state by a special sacrament" (GS 48 § 2).

(The next question is: What happens in Holy Orders?)