Angels are non-sexual,
but all angels in Christianity are referred to as 'he'. There are
female angels in other religious traditions.
The three highest
Choirs or Orders of angels are the Seraphim, Cherubim and Thrones
(or Ofanim). Seraphim have six wings, Cherubim have four. The angels
of these Orders are closest to God, towards whom their main duties
are directed. They sing and praise God, and intercede for His mercy
on behalf of those less fortunate.
The next three
Orders are the Dominions, Virtues and Powers (or Potentates). These
angels are espcially responsible for the ordering of the cosmos
and the regulation of natural phenomena. They guide the courses
of the planets and control rain, wind and snow. They may also regulate
the activities of Heaven and the duties of lower angels.
The three Orders
furthest from God, and therefore closest to humankind, are the Principalities,
Archangels and Angels. Confusing! -- because 'archangels' in a different
sense refers to the mightiest princes in Heaven, while members of
all nine Orders may also be spoken of as 'angels'. (In Ferren and
the Angel, I've relabelled the two lowest Orders as 'Junior Archangels'
and 'Junior Angels'.) These angels are especially concerned with
human affairs. They appear to human beings as bearers of messages,
guardians and advisers.