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."

While the Church itself is the universal sacrament of salvation, the sacraments of the Catholic Church in the strict sense are seven sacraments that "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".

"The Church affirms that for believers the sacraments of the New Covenant are necessary for salvation", although not all are necessary for every individual, and has placed under anathema those who deny it: "If any one saith, that the sacraments of the New Law are not necessary unto salvation, but superfluous; and that, without them, or without the desire thereof, men obtain of God, through faith alone, the grace of justification; - though all (the sacraments) are not indeed necessary for every individual; let him be anathema."

Extracted from the Catechism of the Catholic Church and Wikipedia.