From Destinypedia, the Destiny wiki
Prime Servitors are viewed as gods within their respective Houses, due to the life sustaining Ether they produce. While they were once seen as beacons of hope for the Fallen people in the wake of the Whirlwind, they are now tools of control used by Kells. Servitors within each House are attached to their Prime, and possess unique programming from other Servitors connected to different Primes.
Prime Servitors exist in an unclear symbiosis with Fallen Archons, who act as their caretakers and protectors. It is thought that Prime Servitors may play a key role in Fallen star flight. In some instances, a Prime can act as the leader of a House in the stead of a Kell, however they depend on their Archons to protect them, and their ability to lead is weak.
Known Prime Servitors
Prime Servitor Variants
List of appearances