Schmange is the resident Cubase expert however I think audio path is, in this context, the location of a file on a disk. This is nothing to be afraid of.

It could be that your sound card is looking for an external clock to synch to which is screwing with your sample rates etc and generating noise, jitter and weird artifacts. Try setting the sound card as clock master.

Another thing, does your Boss GT have an S/P DIF out and is there an S/PDIF in on the soundcard ? If so get some 75 ohm video cable with RCA type ends, set either the GT6 or the sound card as master, make sure the sample rates are the same and record guitar digitally.