I can tell by your question you are new to the hydraulics on a tractor. I was there not too long ago, and I too, was thoroughly confused by this option before I bought my 4310.. Everyone here gives great, but sometimes way too technical explanations for the average newbie. Let me attempt to explain (and the veterans of this board can correct me if I am wrong)
Remotes (also referred to as SCV) are valves where the (flow or operation) is <font color="red">CONTROLLED </font> by something like a joystick. This is used for front end loaders, etc. You move the stick, the loader reacts accordingly.
Power beyond is a connection to the hydraulic system where the flow is <font color="green"> NOT CONTROLLED</font> . You would use this with an implement that had it's own flow (or operation) control, such as a backhoe.