Venial Sin vs. Mortal Sin

I know many catholic people are confused about what is the differences in the sins they commit. The Church says there are two types of sins: Venial and Mortal. Venial sins are sins that damage our relationship with God but do not totally destroy it. Mortal sins completely separate us from God and require confession to heal whereas venial sins only require the Eucharist to heal the relationship or just spending time with God in general. Here, the catechism says: 1857 For a sin to be mortal, three conditions must together be met: "Mortal sin is sin whose object is grave matter and which is also committed with full knowledge and deliberate consent." So for a sin to be mortal, it must be a bad sin, it must come about by free will, and the person who commits the sin must know that it is grave and mortal.