Not totally sure, but it may pertain to how many bits the console is sending to your TV for each pixel. Each pixel is made up of different values for each of the Red/Blue/Green (RGB) colors, and that gives you the finalized pixel.
Due to the way bits work, every single bit you add on to a value increase the value by powers of 2. 2/4/8/16/32 and so on. The more bits you use for each pixel, the more bits that are used for each color and thus allow a greater range of colors to be displayed. Newer TV/Monitors will allow for more bits per pixel, while older ones won't.
In short, the more bits per pixel, the better the colors the image will produce. But that's of course if you're TV supports it. If it doesn't, find the highest setting it will display an image on and leave it there. --- This feels warm. What is this feeling? Is it of warmth?