If the codec exists as part of the Avid native codec library, then the clips will basically be a copy wrapped im MXF and managed in the Avid MediaFiles/MXF/ folder structure. If the codec is not, then consolidate will also include a transcode.
A transcode is always converting to the target codec choice for any source codec regardless of being native or not unless they match exactly.
When you select transcode, you can see a list of codecs that are considered native to Media Composer. If your originating codec is not thee, then consolidate will include a transcode. An obvious example would be an R3D file from RED. You can select entire clips, spans of clips (IN-OUT), etc, and the consolidation process will include a transcode to your selected natively supported codec.
Michael
Michael Phillips