It displays the input source, what type of encoding the content is in (stereo, steroeo 2x, DD, DD PL movue, DD PL Music, etc), whether the content is 96/24 (or is it 24/94, i can't remember?). It also is used for displaying the levels of channels. There might be more but I can't remember. I got it for christmas and its currenty back in the box until I move back to my apartment before school starts.