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.  (Catechism of the Catholic Church (CCC), 1131)

Christ instituted the sacraments of the new law. There are seven: Baptism, Confirmation (or Chrismation), the Eucharist, Penance [also called Reconciliation or Confession], the Anointing of the Sick, Holy Orders and Matrimony. The seven sacraments touch all the stages and all the important moments of Christian life: they give birth and increase, healing and mission to the Christian's life of faith. There is thus a certain resemblance between the stages of natural life and the stages of the spiritual life. (CCC, 1210)

There are three sacraments of Christian initiation: Baptism, Confirmation, and Holy Eucharist; two sacraments of healing: Penance (also called Reconciliation or Confession), and Anointing of the Sick; and two sacraments at the service of communion and the mission of the faithful: Matrimony (Marriage) and Holy Orders. This order, while not the only one possible, does allow one to see that the sacraments form an organic whole in which each particular sacrament has its own vital place. In this organic whole, the Eucharist occupies a unique place as the "Sacrament of sacraments": "all the other sacraments are ordered to it as to their end." (see CCC, 1211)