Catholic Church

“The sacrament of penance raises a lot of questions. Can you offer some help? I’ve heard that the penitential rite, which opens the celebration of Mass, grants absolution for venial sins. Is this correct? The code of canon law states that the sacrament of penance is required for grave sins at least once a year, but only recommended (and not required) for venial sins. How can one differentiate a venial from a grave sin?”