My reel has a drag knob and a fighting drag switch thing; what are the differences and when are they used etc?

Please add the reel make and model.

Tom

Shimano Sedona1000RA

Back in the 70's spinning reels introduced rear drags in lieu of front spool drag like Cardinal reels. The rear drag puts pressure directly onto the drive shaft and allows the angler to adjust the drag while fishing without getting near the front line spool. The problem was a slight adjustment made a big drag force change, so anglers stopped using them, returning to front drag reels.

The Shinamo RA was an attemp to resolve the rear drag issue and also have a front spool drag. By moving the rear lever you add or subtract only a controlled amount drag force in addition to the pre set front drag. Sounds good but wasn't accepted by anglers who preferred front drags and the few who prefer rear drags, the reel is no longer offered to he best of my knowledge.

Tom

 

Shimano still offers the fighting drag on some of their rear drag reels. 

The Sahara FI rear drag still has the lever.

To me it was nothing more than a gimmick to sell more reels. After a while most of the levers lost their drag pressure. 

Plus front drag reels had a more consistent drag.

I just don't see the point in messing with your drag in a bass reel. Fighting a 500# tuna I see the advantage but a 5# bass I just don't get. Set the drag hard enough so the hook sets and reel that sucker in.