Ajahs
In the Age of Legends time period of the Wheel of Time series, an Ajah was a temporary group of people banded together for a specific purpose. In the present, or time period of the main plot of the Wheel of Time, the Ajahs are seven sub-societies among which all Aes Sedai, except for the Amyrlin, of the White Tower are divided. These societies each have representatives in the legislation of the Tower, have personal ideologies, customs and purposes for joining, their own ruling heads, and all except the White have networks of spies.
Only the members of a certain Ajah are supposed to know their head's identity. However, the heads of the Ajahs know each other, but this is not widely known.
Read more about this topic: Aes Sedai