Yeah, they send unprocessed signal (no FX, compression, EQ, pan, etc) from each item in your setup individually to a mixer.
Great if you’re using it in a live setting, so your sound tech can have individual control over volume, or the monitor guy can send just kick and snare to the bass player, or whatever, as if it was an acoustic kit all miced up. Cant see a valid common use for it outside of that though; if you were recording, I guess you could route the pieces and apply your processing separately if you really wanted to, but a VST would be a far easier and more flexible way to do that.