This is from Chapter VI, pages 164-165 of the link that Asteriktos gave us:
Theology has given to the Celestial Beings nine interpretative names, and among these our divine initiator distinguishes three threefold Orders.(5) In the first rank of all he places those who, as we are told, dwell eternally in the constant presence of God, and cleave to Him, and above all others are immediately united to Him. And he says that the teachings of the holy Word testify that the most holy Thrones and many-eyed and many-winged ones, named in the Hebrew tongue Cherubim and Seraphim, are established
immediately about God and nearest to Him above all others. Our venerable hierarch describes this threefold Order as a co-equal unity, and truly the most exalted of the Hierarchies, the most fully Godlike, and the most closely and immediately united to the First Light of the Godhead.
The second, he says, contains the Powers, Virtues and Dominions, and the last and lowest choirs of the Celestial Intelligences are called Angels, Archangels and Principalities.
Then he goes into detail describing them all.