Originally Posted by sevendaysoff
dither fills in all the extra bit depth when you use sample rate conversion I believe. Takes out all the digital distortion & noise from the sample rate conversion.
If you record/mix at 48 24bit but want to bounce to a CD at 44.1 16, or you're mastering a track for CD, you use dither.
Actually, dither is adding noise. Or, more precisely, dither IS noise. Nor does it have anything to do with sample rate conversion; only bit depth. It's also not filling in extra bit depth, more like...pushing the existing audio up a few bits (working from the bottom up, as opposed to the top down), sorta, but I gotta run so I can't get too into it.
To the OP: Google it or Wikipedia it for some really good, easy-to-understand answers.
EDIT: OK, I'm back. Here's the first page that came up when I typed "Audio Dither" into Google: Digital Audio: Dither
Looks like it's got some pretty good, easy-to-understand stuff. And it certainly explains things better than I could've.
EDIT AGAIN: Go buy Bob Katz's book "Mastering Audio". Everyone who wants to buy a DAW should be required to take a test using that book as gospel before they're allowed to even turn on the computer.
OK. I had a little too much coffee this morning. I'm done.