Well, im looking at purchasing a stage 3 12" rockfard subwoofer. The only confusion i am having is they sell 2 subwoofers exactly the same, only difference is one is 4 ohms and the other is 2 ohms. Which is the better subwoofer? (i dont understand OHMS obviously)

it's for wiring to your amp(s) and how stable the amp is. There's different ways to wire so there will be diff loads (ohms) on your amp. generally the lowest stable (usually 1 or 2 ohms) on your amp will give you the most power. dual 4 and dual 2 ohms will cause different loads on your amp.

http://www.cardomain.com/item/ROCP312D2 Click on the Subwoofer Wiring Guide on the right of the screen. That should help you out a bit