Sacraments confer grace based on the belief of ex opere operato / ex opere operatus, which means they work by the very grace of God and are not dependent upon the worthiness of the minister or the recipient. By the very fact that a priest or person intends to do what the Church intends means the sacraments work. For a sacrament to be considered "valid and licit" two things must be present. The proper matter and form need be used. If the proper matter is not used, the sacrament is invalid. If the proper form is not used, the sacrament is illicit. The sacraments also need to be performed by the proper minister with the faculties to perform it. In some situations, others, including in some cases, the laity, may be given permission to act as extraordinary ministers of the sacraments. The matter, simply put, is the material used for the sacrament, for example, water for baptism. It is the sensible, visible part of the sacrament. The form or formula is the prayer that goes with the sacrament, for example, "I baptize you in the name of the Father and of the Son and of the Holy Spirit."
The seven sacraments are Baptism, Reconciliation, Eucharist, Confirmation, Marriage, Holy Order and Anointing of the Sick.