Reconciliation - Confession

It is called the Sacrament of Penance, since it consecrates the Christian sinner’s personal and ecclesial steps of conversion, penance, and satisfaction… CCC 1423
 
It is called the Sacrament of Confession, since the disclosure or confession of sins to a priest is an essential element of this sacrament…It is called the sacrament of Reconciliation, because it imparts to the sinner the love of God who reconciles… CCC 1424
 

“Those who approach the sacrament of Penance obtain pardon from God’s mercy for the offense committed against him, and are at the same time, reconciled with the Church which they have wounded by their sins and which by charity, by example, and by prayer labors for their conversion.”

Lumen Gentium 11 § 2.