- The Roman Catholic Church has major orders (bishops, priests, deacons and subdeacons), and (until they were abolished in 1972) minor orders (acolytes, readers (or 'lectors'], exorcists and porters (doorkeepers or ostiarii).
- The Anglican Church recognizes only the three holy orders of bishop, priest, and deacon.
- Most branches of the Eastern Orthodox Church recognize the orders of bishop, priest, deacon, subdeacon and ἀναγνώστης‚ (anagnostes) or reader. Some also have ψάλτης‚ (psaltes), or singer.
- Most Protestant churches describe their professionals as ministers of religion. They do not rank them as strictly as the older churches.
Holy Orders is also the name by which the Roman Catholic church knows the sacrament more usually called ordination: the rite by which a candidate is admitted to the relevant order. This is known less formally in other churches as 'taking orders', or 'taking holy orders'.
- Do not confuse the slightly different terms Holy Orders and Religious orders. A religious order is a community of people who have taken certain vows and live under a common rule of how to live their lives. The two terms can overlap considerably - most members of the Benedictine Order (Benedictines) and Society of Jesus (Jesuits) are also priests - members of a major order.