| Term | Definition |
| Apostolic | The belief that the Church can only be understood in the light of the Apostles |
| Catholic | universal or worldwide |
| Holy | Of, or relating to, God. Sacred. |
| Body of Christ | The belief that the Church is Christ's body in the world continuing his work |
| Communion of Saints | All Catholics, both alive and dead, are joined together (and can pray for one another) |
| Bishops | Priests who have a special vocation and are chosen by the Pope. They are responsible for all the churches in a diocese. |
| Deacons | Those called to assist bishops, especially in caring for the needy. |
| Magisterium | The Pope and bishops interpreting the Bible and tradition for Catholics today. |
| Papacy | The office of the Pope |
| Priests | Specially called chosen people who are ordained to be ministers of the sacraments |
| Laity | Those who share the mission of the Church without being ordained |
| Celibacy | Living without engaging in any sexual activity |
| Ordination | Making someone a priest, bishop or deacon by the sacrament of Holy Orders |
| Bible | The Holy Book of Christians with 66 books split into Old and New Testaments |
| Apostolic Succession | The belief that the bishops and the Pope continue the mission Jesus gave to Peter and the Apostles |
| Dogmas | The beliefs of the Catholic Church |