Catechism of the Catholic Church §1491 — excerpt
The sacrament of Penance is a whole consisting in three actions of the penitent and the priest's absolution. the penitent's acts are repentance, confession or disclosure of sins to the priest, and the intention to make reparation and do works of reparation.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.