Well, in the perspective of the Bible (the Old Testament), Passover was a time of remembrance of the Hebrew's freedom from Egyptian oppression. The name itself comes from the last of the Ten Plagues, where death came down and killed all first born. In order for death to "pass over," the Hebrews painted lamb's blood on their doors. So hence all Egyptian first born were killed, including Pharaoh's. That is the foundation of Passover, but any influence or importance to Catholics and branching Protestant beliefs is unknown to me.
Hope this helps
