A sacrament is "an efficacious sign of grace, instituted by Christ and entrusted to the Church, by which divine life is dispensed to us through the work of the Holy Spirit (774, 1131). The sacraments (called "mysteries" in the Eastern Churches) are seven in number: Baptism, Confirmation, Eucharist, Penance or Reconciliation, Anointing of the Sick, Holy Orders, and Matrimony" (CCC #1131, 1210).

Read: The Seven Sacrements of the Catholic Church by Bishop O'Connell