Thanks for your enlightening responses, cyrano.
I have the .rpp files corresponding to projects I'm currently working on, so that part's clear. Excuse my ignorance, but I'm unsure what a media file is, or where to find it. And when I do, will it be clear which media file corresponds to which .rpp file?
If this is getting tedious, no probs - appreciate your help, whatever. I've done a bit of googling and this page looks like something I need to investigate:
http://reaperblog.net/2013/07/reaper...le-management/
Cheers!