Confession

It is called the sacrament of repentance because it sacramentally fulfils the repentance that Jesus calls for (cf. Mk 1:15), the step of returning to the Father (cf. Lk 15:18) from whom one has strayed through sin.

It is called the sacrament of penance because it represents a personal and ecclesial step of repentance, regret and satisfaction for the sinful Christian.

It is called the sacrament of confession because the confession, the confession of sins before the priest, is an essential element of this sacrament. This sacrament is also a confession in the sense of recognising and praising the holiness of God and his mercy towards sinful man.

It is called the sacrament of forgiveness because, through the priest’s sacramental absolution, God grants ‘remission and peace’ to the penitent (OP, formula of absolution).

It is called the sacrament of reconciliation because it grants the sinner the reconciling love of God: ‘Be reconciled to God’ (2 Cor 5:20). Those who live by the merciful love of God are ready to respond to the Lord’s call: ‘Go, first be reconciled to your brother or sister’ (Matt 5:24).

~ from the Catechism of the Catholic Church (1423-1424)
A confession mirror for examining your conscience and preparing for confession can be found here