The text below is from The Catechism of the Catholic Church. Paragraph numbers refer to the sections of the Catechism.
1113 The whole liturgical life of the Church revolves around the Eucharistic sacrifice and the sacraments. There are seven sacraments in the Church: Baptism, Confirmation, Eucharist, Penance, Anointing of the Sick, Holy Orders, and Matrimony.
1118 The sacraments are “of the Church” in the double sense that they are “by her” and “for her.” They are “by the Church,” for she is the sacrament of Christ’s action at work in her through the mission of the Holy Spirit. They are “for the Church” in the sense that “the sacraments make the Church,” since they manifest and communicate to men, above all in the Eucharist, the mystery of communion with the God who is love, One in three persons.
1119 Forming “as it were, one mystical person” with Christ the head, the Church acts in the sacraments as “an organically structured priestly community.” Through Baptism and Confirmation the priestly people is enabled to celebrate the liturgy, while those of the faithful “who have received Holy Orders, are appointed to nourish the Church with the word and grace of God in the name of Christ.”
1131 The sacraments are efficacious signs of grace, instituted by Christ and entrusted to the Church, by which divine life is dispensed to us. The visible rites by which the sacraments are celebrated signify and make present the graces proper to each sacrament. They bear fruit in those who receive them with the required dispositions.