The highest choir of angels. These are the angels who are attendant before God's throne, cf. Isaiah 6:1-7.
Thrones are described as Angels of Humility and Peace.
Powers are Warrior Angels, defending the cosmos and humans from evil spirits who attempt to wreak chaos.
Archangels are those most frequently mentioned in scripture. They have a unique role as God's messengers to people at critical times in salvation history, such as in The Annunciation.
These angels are the lowest rank of angel. They are described as caring and as giving help to those in need.