Don't you think I've tried that? Googling something is the first thing I would do. Everything all the searches came up with means nothing to me. I guess it was too much to ask for some help.
Well I told you about the two main formats on the Mac, but your reply seemed pretty dismissive. If you want formats to use on iPods etc. then you're stuck with aac, mp3 or Apple lossless - so information about anything else will be a waste of time.
Give some more details. What are you trying to do? Have you experimented yourself with different compression to see if you can hear the difference?
Oh right, I didn't know they where the main ones, like I said I don't know much about it. What I was on about with the second post is what about FLAC and some of the formats which I keep seeing in posts.
I have had a listen between Mp3 128 and Mp3 192 I think, honestly I can't really hear a difference. Basically I just want to see all the options I have for compressing music.