what is different between joint-stereo,dual stereo and stereo in mp3?

[alanleung]

what is different between joint-stereo,dual stereo and stereo in mp3?
when converting a mp3 file,it need to choose a channel mode.
so will it effect mp3 file size?

[Spoon]

It won't affect the size, rather than the quality (joint stereo should give the best quality).