Confession (or Reconciliation or Penance) is the Sacrament in which we receive forgiveness from Christ. We repent and confess our sins, and are absolved of sin through the ministry of a priest, who acts in the person of Christ when he pronounces the words 'I absolve you from your sins in the name of Father and of the Son and of the Holy Spirit.'
Confession is our way of repairing our relationship with God. 'I am the vine, you are the branches. Those who abide in me and I in them bear much fruit, because apart from me you can do nothing.' John 15:5 Just like with a branch of a vine we can become cut off, when away we cannot thrive or bear fruit, but a vine branch can be grafted back to the vine
Jesus said to his apostles; ‘Receive the Holy Spirit. If you forgive the sins of any, they are forgiven; if you retain the sins of any, they are retained' John 20:19, 22-23
The priest is an instrument of Christ. He hears the confession, offers some advice, gives a penance and absolves the penitent. Everything said in the Confession is held under the Seal of Confession and kept in confidence between you and your confessor.
'The sacramental seal is inviolable; therefore it is absolutely forbidden for a confessor to betray in any way a penitent in words or in any manner and for any reason.' Can. 983
“Repent, and be baptized every one of you in the name of Jesus Christ so that your sins may be forgiven; and you will receive the gift of the Holy Spirit."