The Catholic Church divides sin into two categories: venial sins, in which guilt is relatively minor, and the more severe mortal sins. Theologically, a mortal sin is believed to destroy the life of grace within the person and thus creates the threat of eternal damnation. "Mortal sin, by attacking the vital principle within us - that is, charity - necessitates a new initiative of God's mercy and a conversion of heart which is normally accomplished [for Catholics] within the setting of the sacrament of reconciliation."
The Deadly Sins do not belong to an additional category of sin. Rather, they are the sins that are seen as the origin ("capital" comes from the Latin caput, head) of the other sins. A "deadly sin" can be either venial or mortal, depending on the situation; but "they are called 'capital' because they engender other sins, other vices."