The official, definitive and in-depth instruction on the Sacraments of the Catholic Church from articles 1113 to 1134 in the Catechism of the Catholic Church. It elaborates the commonalities of all seven Sacraments.
Article by John Hardon, S.J., focuses on understanding the Sacraments. They are listed and briefly defined, then the responsibilities of believers are described in relation to our time.
The seven Sacraments listed with links to articles about each: Baptism, Eucharist, Reconciliation, Confirmation, Marriage, Holy Orders, Anointing of the Sick