It means those are the specs on that amp. In other words, what it is supposed to put out at those ohms. Depending on the brand, those could be accurate or WAY off. Old Peaveys used to be notorious for under rating their power amps. I had an old CS 400 that was rated 200 watts per side at 8 ohms. Had to have it fixed one time and when they bench tested it, it was putting out 265 on one side and 275 on the other. There are many different factors when it comes to how loud an amp really is. We were playing an outdoor gig one time and my bass player set up an Ampeg fliptop 100 watt amp with a 15" cab, a Fender 300 watt bass head running two 15" cabs, and an Acoustic 200 watt bass head running a two 10" cab. He had it set loud and was shaking the stage. I set up my little '62 Fender Deluxe (rated 20 watts) and a Fender Eighty Five, both of which were 12" combos, with my Zoom digital multieffects pedal. I started jamming around with the amps set on about 3. After a bit, I noticed my bass player tweaking his amps again and asked him what he was doing. He said he was trying to get more volume so he could hear it over my rig.
