I'm currently re-watching Voyager and there are two occasions (so far—I don't think there are any more?) when members of Voyager visit the Q Continuum. On both occasions it is said that what they see is simply a representation that they can understand and the true nature of the Continuum is beyond their comprehension.
In The Q and the Grey, Janeway and later other members of the crew interact with what they see the Continuum as. Voyager also apparently travels to the Continuum by flying directly in to one of the supernovae which are apparently echoes of the battle in the Continuum... which suggest that the crew do actually physically travel to the Continuum.
Is that the case? I originally thought it may just be their consciousness which was "transported" to the Continuum, but Voyager physicially travelling there seems to suggest otherwise.
So, are the non-Q species that visit the continuum actually physically there and if so what are they actually physically doing whilst there, as what they are seeing and experiencing isn't "real"?
(I've got a suspicion that this isn't addressed and the answer is; nobody really knows)