the angelic orders

First Sphere

The first sphere angels serve as the heavenly servants of God the Son incarnated.

Seraphim

Seraphim (singular "Seraph") literally translated "burning ones", the word seraph is normally a synonym for serpents when used in the Hebrew Bible.

Cherubim

Cherubim have four faces: one of a man, an ox, a lion, and an eagle (later adopted as the symbols of the four evangelists). They have four conjoined wings covered with eyes, a lion's body, and the feet of oxen. Cherubim guard the way to the tree of life in the Garden of Eden.

Thrones

The "Thrones" (Greek: thronoi, pl. of thronos), or Elders, are a class of celestial beings. They are living symbols of justice and authority, and have as one of their symbols the throne.

It is not unusual to find that the Thrones are associated, by some, with the Ophanim or Erelim from the Jewish angelic hierarchy, however there is very little evidence, if any, to sustain this idea.

Christian theologians that include the Thrones as one of the choirs don't describe them as wheels, describing them as adoring elder men who listen to the will of God and present the prayers of men. The Twenty Four Elders in the Book of Revelation are usually thought to be part of this group of angels.

Second Sphere

Angels of the Second Sphere work as heavenly governors of the creation by subjecting matter and guiding and ruling the spirits.

Dominions or Lordships

The "Dominions"  (lat. dominatio, plural dominationes, also translated from the Greek term kyriotētes, pl. of kyriotēs, as "Lordships") or "Dominations" are presented as the hierarchy of celestial beings "Lordships" in some English translations of the De Coelesti Hierarchia. 

The Dominions regulate the duties of lower angels. It is only with extreme rarity that the angelic lords make themselves physically known to humans.

The Dominions are believed to look like divinely beautiful humans with a pair of feathered wings, much like the common representation of angels, but they may be distinguished from other groups by wielding orbs of light fastened to the heads of their scepters or on the pommel of their swords.

Virtues or Strongholds

These angels are those through which signs and miracles are made in the world.

The term appears to be linked to the attribute "might", from the Greek root dynamis (pl. dynameis), which is also translated as "Virtue" or "Power". They are presented as the celestial Choir "Virtues", in the Summa Theologica.

"The name of the holy Virtues signifies a certain powerful and unshakable virility welling forth into all their Godlike energies; not being weak and feeble for any reception of the divine Illuminations granted to it; mounting upwards in fullness of power to an assimilation with God; never falling away from the Divine Life through its own weakness, but ascending unwaveringly to the superessential Virtue which is the Source of virtue: fashioning itself, as far as it may, in virtue; perfectly turned towards the Source of virtue, and flowing forth providentially to those below it, abundantly filling them with virtue."

Powers or Authorities

The "Powers" (lat. potestas (f), pl. potestates), or "Authorities", from the Greek exousiai, pl. of exousia. The primary duty of the "Powers" is to supervise the movements of the heavenly bodies in order to ensure that the cosmos remains in order. Being warrior angels, they also oppose evil spirits, especially those that make use of the matter in the universe, and often cast evil spirits to detention places. These angels are usually represented as soldiers wearing full armor and helmet, and also having defensive and offensive weapons such as shields and spears or chains respectively.

Third Sphere

Angels who function as heavenly guides, protectors, and messengers to human beings.

Principalities or Rulers

The "Principalities" (Latin: principati) also translated as "Princedoms" and "Rulers", from the Greek archai, pl. of archē, are the angels that guide and protect nations, or groups of peoples, and institutions such as the Church. The Principalities preside over the bands of angels and charge them with fulfilling the divine ministry. There are some who administer and some who assist.

The Principalities are shown wearing a crown and carrying a sceptre. Their duty also is said to be to carry out the orders given to them by the upper sphere angels and bequeath blessings to the material world. Their task is to oversee groups of people. They are the educators and guardians of the realm of earth. Like beings related to the world of the germinal ideas, they are said to inspire living things to many things such as art or science.

Archangels

The word "archangel" comes from the Greek ἀρχάγγελος (archangelos), meaning chief angel, a translation of the Hebrew רב־מלאך (rav-mal'ákh) It derives from the Greek archein, meaning to be first in rank or power; and angelos which means messenger or envoy.

In most Christian traditions Gabriel is also considered an archangel, but there is no direct literal support for this assumption. It is also worth noting that the term 'archangel' appears only in the singular, never plural, and only in specific reference to Michael.

The Seven Archangels are said to be the guardian angels of nations and countries, and are concerned with the issues and events surrounding these, including politics, military matters, commerce and trade: e.g. Archangel Michael is traditionally seen as the protector of Israel and of the ecclesia.

It is possible to make a distinction between archangel (with a lower-case a) and Archangel (with an uppercase A). The former can denote the second-lowest choir (arch-angels in the sense of being just above the lowest Choir of angels that is called only "angels") but the latter may denote the highest of all the angels (i.e., Arch-angels in the sense of being above all angels, of any Choir. The seven highest Seraphim, Michael, being the highest of all).

Angels

The "angels" or malakhim, i.e. the "plain" angels (ἄγγελοι, pl. of ἄγγελος, angelos, i.e. messenger or envoy), are the lowest order of the angels, and the most recognized. They are the ones most concerned with the affairs of living things. Within the category of the angels, there are many different kinds, with different functions. The angels are sent as messengers to humanity. Personal guardian angels come from this class.