Mixing : Mixdown : Bounce Options : Convert During or After Bounce

Convert During or After Bounce
The Bounce to Disk dialog can perform any conversion options, including sample rate and bit depth conversion, during a bounce or post-bounce.
The following options are only available when bouncing to a different file type, format, resolution, or sample rate.
Convert During Bounce
This option may take less time than Convert After Bounce, but does so at the expense of plug-in automation playback accuracy.
Convert After Bounce
The Convert After Bounce option, though it takes more time, offers the highest level of plug-in automation accuracy possible.