In the angelology of different religions, a hierarchy of angels is a ranking system of angels. Higher ranks have more power or authority over lower ranks, and different ranks have differences in appearance, such as varying numbers of wings or faces.
Angelic hierarchy in Judaism
The Jewish angelic hierarchy is established in the Hebrew Bible, Talmud, Rabbinic literature, and traditional Jewish liturgy. They are categorized in different hierarchies proposed by various theologians. For example, Maimonides, in his Mishneh Torah or Yad ha-Chazakah: Yesodei ha-Torah, counts ten ranks of angels.
Angels in Christianity
The most influential Catholic angelic hierarchy was that put forward by Pseudo-Dionysius the Areopagite in the 5th or 6th century in his book De Coelesti Hierarchia (On the Celestial Hierarchy). Dionysius described nine levels of spiritual beings which he grouped into three orders:
Highest orders
Seraphim
Cherubim
Thrones
Middle orders
Dominions
Virtues
Powers
Lowest orders
Principalities
Archangels
Angels
During the Middle Ages, various schemes were proposed, some drawing on and expanding on Pseudo-Dionysius, others suggesting completely different classifications.
Pseudo-Dionysius (On the Celestial Hierarchy) and Saint Thomas Aquinas (Summa Theologiae) drew on passages from the New Testament, specifically Ephesians and Colossians 1:16, to develop a schema of three Hierarchies, Spheres or Triads of angels, with each Hierarchy containing three Orders or Choirs. Saint Bonaventure summarized their nine offices as follows: announcing, declaring, and leading; regulating, enforcing, and commanding; receiving, revealing, and anointing. Thomas agreed with St Jerome's commentary on that every living human possesses a guardian angel. Of the angelic orders, he asserted that only the first five are sent by God to manifest themselves in the corporeal world, while the four highest remain in Heaven at His presence.
Angels in Islam
There is no standard hierarchical organization in Islam that parallels the Christian division into different "choirs" or spheres, and the topic is not directly addressed in the Quran.