New to fishing question

I'm new to fishing and don't know much about reels and lines, but, I have a reel that the specs says has a line capacity of 14/215 and a line weight rating of 8lb-20lb, does that mean that I can run 20lb line and that I would just have to use less so I'm not to overfill the reel or is it more optimal to run 14lb line? I'm planning on primarily fishing for bass and catfish. TIA