A naval auxiliary is any military space vessel which is not Naval Rated. By definition these ships are too small to carry heavy weapon systems, and are generally un-crewed and develop thrust from electrothermal plasma thrusters and Fuel Pathing.
By far the most common are military grade Drone operating as a semi-autonomously swarm under the control of a synth. Limited propellant and are moved into the battlefield by larger vessels. The two most common roles types are:
Kamikaze: Loitering munitions, shrapnel (move to intercept course and break into thousands of fragments), cycler
coasters (launched into a high velocity cycler orbit before combat with enough fuel to delta to a potential battlefield at that velocity for a high speed strike).
mirrors (direct energy weapons from slow moving capital ships onto multiple fast moving targets).
Guardian: Small poorly equipped task groups rely on drones as screens to intercept incoming ordinance, and even better
equipped navies make use of fast drones as an outer point defense system to attempt missile intercepts. Shields can deploy expandable inflatable walls on multiple sides of larger ships to hide them from view and absorb some attacks.
Static auxiliaries do not produce enough thrust to dramatically change orbits, this category covers assets like defense platforms and attack satellites. Transports include atmosphere landing craft, troop and vehicle transport, and special ops fast orbital insertion drop-pod carriers. Logistics ships cover hospital ships and dedicated refuelling, ammunition supply, and life support replenishment craft.
Javelin class ships are simple payload delivery vessels. The first type are tubes - metal tubes containing an engine and a payload. Payloads can be missiles, drones, or kinetic weapons launched with the ships velocity. The second type are cannonballs, large blocks of ice with an engine accelerated up to high velocities in cycler orbits with enough fuel to steer them to crash into a large, slow target when needed.
Cutters are light ships that excel at close range orbital combat (cutting lasers, kinetic weapons, grappling satellites). They can also be used for debris ablation and tugboat duties. They are common in the belt where there is little need for big engines, and for constabulary duties. Generally un-crewed except for some police cutters and a few FreeHab colony defense class ships.
Corvettes are an uncommon light ship which a few navies field to perform short range light transport duties, as light missile boats, or as a short range area denial vessel. They are more commonly used for policing in LEO. Generally un-crewed except for VIP and SWAT team transports.