While all of these words can be translated "mystery," the Latin mysterium often refers more to the invisible or hidden dimensions, while sacramentum seems to refer more to the visible or symbolic aspects of a spiritual or divine mystery.

In a sense, Jesus Christ can be called the "mystery of salvation" or the "sacrament of God," since he, through his incarnation, made visible to us the mystery of the invisible God. Similarly, the Church as a whole is sometimes called the "sacrament of salvation," since it is "the sign and the instrument of the communion of God and men" (CCC, §780; cf. §§774-776).

Usually, however, the word "sacrament" refers to seven particular rites or rituals performed in and by the Church.

• Many older Catholics will still remember the very brief definition from the Baltimore Catechism (1941): "A sacrament is an outward sign instituted by Christ to give grace." (§304).
• The current official Catechism of the Catholic Church (1994; 2nd edition 1997), gives a slightly more complete definition: "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." (CCC, §1131; see also "Sacrament" in the CCC's Glossary).
• These sacraments are considered "Sacraments of Christ," "Sacraments of the Church," "Sacraments of Faith," "Sacraments of Salvation," and "Sacraments of Eternal Life" (§§1113-1130).
• The seven sacraments can be subdivided, with three "Sacraments of Christian Initiation" (Baptism, Confirmation, Eucharist); two "Sacraments of Healing" (Penance/Reconciliation and Anointing of the Sick); and two "Sacraments of Vocation" (Holy Orders/Ordination and Matrimony/Marriage; also referred to as "Sacraments at the Service of Communion")

The adjective "sacramental" might refer to something related to the seven official rites: "sacramental preparation," "sacramental action," etc. Yet it can also be used more broadly: for example, the "sacramental imagination" or "sacramental principle" refers to the Catholic Christian conviction in general that invisible spiritual realities can be disclosed or made visible in and through created realities that function as symbols (see Rausch, Catholicism in the Third Millennium, p. 85). These can be considered "real symbols," in that they truly manifest and convey the divine graces that they symbolize, rather than "mere symbols," which simply point to divine realities outside themselves. Religious symbols are not merely intellectual, but also speak to us affectively and intuitively; they can "raise our minds and hearts to God" (ibid.).

The adjective "sacramental" should not be confused with the more rarely used noun "sacramental." A sacramental can be a simple ritual action, religious symbol, devotional object, or short blessing or prayer (for example, making the sign of the cross, sprinkling something with holy water, receiving ashes on the forehead on Ash Wednesday, lighting candles, going on a religious pilgrimage, wearing religious clothing, using a statue or icon or other artwork for devotional purposes, etc.). Such "sacramentals" can make us aware of divine realities (or, vice-versa, make divine realities present to us), although they can also be abused or become superstitious.

The noun "sacramentality" is the overall concept, the idea or conviction that God can be encountered in symbolic/sacramental ways. (Compare other words ending in "-ty", such as "reality" or "sexuality," which are overall concepts for anything having to do with the "real" or "sexual" dimensions of life, respectively).

Analysis and Explanations:

While many Protestant Churches regard only Baptism/Initiation and Eucharist/Communion as the two core Sacraments (directly instituted by Christ), Catholic Church (and most Orthodox Churches) officially recognizes the following seven sacraments (CCC, §§1113, 1210-1666), listed below with brief comments about their biblical backgrounds, the words and actions involved, their effects, and who can administer each of them.  Christ Catholic Church follows all seven (7) Sacraments: