What are these connections?

I'm thinking of buying this mobo http://www.newegg.com/Product/Product.aspx?Item=N82E168... with a i5-3350P because its a bit of an upgrade from my current i5 650. NOw I know what the one labeled "HD_AUDIO1" is, the "CHA_FAN_1" is case fan, obviously, I think I see the connections for power, hdd activity, reset, etc. I have NO idea that the ones labeled B_4_-, B_6_-,IR1, and if you look, just to the lower right of the lowest pcie x1 slot there is a small 9 pin header above a usb header, what is it? also there is what appears to be the same thing just pslit up above the power and reset buttons on the lower right of the board.