The Catechism of the Catholic Church defines the sacraments as "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." A sacrament is "an outward and visible sign of an inward and spiritual grace given unto us, ordained by Christ himself, as a means whereby we receive the same, and a pledge to assure us thereof".
The Catholic Church teach that the sacraments are seven. The Catholic Church understands the word "sacrament" as referring not only to the seven sacraments considered here, but also to Christ and the Church.
Our crucifix, icons and other articles are examples of what we call sacramentals. According to the Catechism of the Catholic Church, sacramentals are sacred signs instituted by the Church to prepare us to receive the fruit of the sacraments and to sanctify different circumstances of our lives (no. 1677).
Practically speaking, the myriad of little things that are sacramentals are the parts of catholicity that jostle against us in our everyday life, those little extras that often tell others we are Catholic. They are the images, actions and blessings that are unique to our faith; those sometimes humble reminders of what the Catholic faith is all about, like the crucifix on our wall.