Cherubim: the Cherubim are the heavenly counselors who work above the Thrones in the angelic hierarchy. They are the guardians of the Light throughout the universe. They usually do not have much personal contact with beings on Earth.
The highest of the nine orders of angels. In the Old Testament they appear as God's attendants, e.g. they guard his presence from profanity, and representations of them were set up in Solomon's Temple at Jerusalem, overshadowing the ark (Cross, The Oxford Dictionary Of The Christian Church).
In the Bible the Cherubim appear as distinct from the angels who are Jehovah's messengers, while the Cherubim are found where God is personally present: e.g. "And he [God] rode upon a cherub." (Psalms 18:10). Figures of Cherubim were wrought into the hangings of the Holy of Holies and were represented above the Mercy Seat within. In later tradition, the Cherubim were included among the nine orders of angels.
One of the second highest order of Angels. In the Divine Liturgy we approach the Heavenly Throne of Christ and thus join in with the Angels in singing praise to God. The Hymn which reminds us of this calling is called the Cherubimic Hymn and it begins: "Let us who mystically represent the Cherubim..."