| Term | Definition |
| Cohabitation | living together without being married |
| Marriage | A man and woman legally joined so that they are allowed to live together and, usually, have children |
| Adultery | having sex with someone other than your marriage partner |
| Pre-marital sex | sex before marriage |
| Promiscuity | having sex with a number of partners without wanting a relationship with them |
| Faithfulness | staying with your marriage partner and having sex only with them |
| Remarriage | marrying again after being divorced |
| Annulment | a declaration by the Church that a marriage never lawfully existed |
| Homosexuality | sexual attraction to the same sex |
| Extended family | children, parents and grandparents/aunts/uncles living as a unit or very near to each other |
| Nuclear family | mother, father and the children living as a unit |
| Re-constituted family | where two sets of children (stepbrothers and sisters) become one family when their divorced parents marry each other |