How does angular orientation drive work with 2 phys

There is very little information on how angular orientation drive works. I do understand that it applies a force to get something in a certain orientation… but what? I have two physics simulator actors with a constraint. So what orientation is it concerned about? The first actor, the second actor, both? the orientation between then? are orientations relative to the world, or to the other actor, or something else?
Can someone explain a little about this? There is very little information in the manual about this…

Thank you very much!

What I have learned so far is that constraints use reference frames for both objects that are constrained. These are transforms, but I assume only the location and rotation are used. Those reference frames are created based on the objects position and rotation when the constraint is created / instantiated. If you call SetConstrainedComponents they will be created again with the current position and orientations of the objects as references frames.

Then the constraints will try to keep the relative position and rotation between the objects the way they are set in the reference frames, with possible freedom in some positional or rotational axis, and with possible orientation or location motors to keep them in place in a more ‘soft’ way. And it seems that the relative rotation between objects is calculated with the position of the physics constraint as the pivot point. For the locational constraints, the position of the contraint doesn’t seem to matter, but correct me if I’m wrong.

This sort of information should be in the Unreal Engine documentation! I’d had to figure this out by experimenting, and I’m not even sure now my information is 100% correct. Please explain more in the documentation how things actually work in the engine, and what all the parameters means that you can set.