The 2 pairs of connections - or binding posts as we usually call them - allow the speakers to be bi-wired or bi-amped. One set of binding posts is for bass signals and the other is for mid to high frequency signals. This means running 2 sets of identical-length speaker wires from your amp or receiver to your speakers. You have to remove the jumper connection first before you do this. The advantage of bi-wiring is you isolate the strong bass signals so they don't overwhelm the lesser-intensity mid to high frequancy signals. The result is a clearer, cleaner, purer and a more focused and articulate sound.
