It involves three elements: confession, penance, and reconciliation. In confession, the penitent makes a verbal admission of his/her sins. Afterwards, the priest absolves the penitent’s sins and asks him/her to perform an act of reparation or penance for the sin committed.

What are the Rules of Confession as Per Law
Confession Process & Requirements
There must be sin.
The penitent has sorrow for sin (imperfect contrition)
The penitent is willing to do penance.
The penitent is willing to make satisfaction if needed (esp. stealing, lying)
The priest must give Absolution.