RoboLoftie, you have to admit that MS PR is very simplistic. For them, Denim is everything the updateS bring. Updates with an S.
But technically, OS and FW are different, Denim is the FW for Lumias. Again, 930 users have received GDR1 (8.1.1) along with a FW update, which remained Cyan. I have received a Cyan update on my 1020 in September (and no OS update), 1 month after the 8.1/Cyan roll out.
The Black FW brought RAW capacity to the Pureview devices, it wasn't linked to the OS.
MS are making this complicated, when they list, in the Denim benefits, the features coming from the OS. Denim will bring features related to Bluetooth, low-level camera changes, etc. "Drivers", if you want to compare to a regular desktop PC.
Now back to the guy asking "do you have Live Folders?". If it was Denim, one would have Live Folders. But having Live folders doesn't mean you have Denim. The question was, to my eyes, more to be sure it's Denim. But checking for live folders is not the right way to do it.
The only way is to go into about (in settings) and read the FW version. This won't lie ^_^