Does it affect just macroblocking? Or does it also throw out other information? Usually when I read a definition for bit rate, it's something like, 'it affects quality'. I understand that, but I'm curious as to exactly which piece of information from the video is thrown out. I think the same amount of pixels are used regardless of bit rate so my guess is that resolution (pixels) is tied directly with bit rate, and if there's not high enough of a bit rate, it'll throw out color information from certain pixels and color others the same, resulting in blocks. Am I correct on that?

This also makes me wonder how bit rate ties to frame rate. If you have a hypothetical 300fps video with a low bit rate, to display all of those frames, it'd have to throw out some information. What information is what I want to know. The same as my guess above?