Surround Speaker Confusion with Denon Receiver

Hope someone can clear this up for me. I have a Denon AVR 3300, 5.1 receiver. It actually has 2 side channel speaker connections (left and right side) but it also has 2 additional side channel connections so you could actually have a 7.1 configuration. My question is this, does anyone know if the 2 additional connections are discrete rear left and right signal channels or are they just receiving the same side signal as the 2 side channels, in other words is this a true 7.1 reciever or just a 5.1 reciever with extra side channel channels? Thank you for clearing this up for me.

Golfnut