Confession is an admission. 
This type of confession is a Roman Catholic ritual. You go into a booth, tell the Priest the bad things you have done, and he absolves your Sins. The confession system keeps ordinary Roman Catholics dependent on their priests because they believe they need confession and absolution to get right with God.
- The priest may get a few Sexual kicks out of listening to the sexual sins of young Girls and Women if he's Heterosexual.
- The priest may get a few Sexual kicks listening to the sexual sins of young Men and Boys if he's Gay.
Of course, the person often goes back to doing what they were doing before as no one is perfect.
Confession in law
A confession can also be an admission of that a person has done a criminal act and if the confession is admissible in court it can lead to conviction and punishment. Torture and psychological pressure is sometimes used to get false confessions out of prisoners and innocent people are sometimes punished after false confessions.