The undelete scan searches for deleted files in the UNUSED portion of the device, as reported by the Bitmap of the file system. It does not scan the used portion (where normal, not deleted files are) of the drive at all, so all files found have been previously deleted. The results you’ll get include all files that were deleted, and old saved versions of them too.

So if a file recovered is “the exact same” as a file you already have. It is either a deleted copy of the file you currently have, or it could be that you just don’t notice the differences between the two files. As a side note, the Undelete Scan will not be able to recover the file names of files due to the limitations of HFS and HFS+ filesystems.

Note, this is for Mac systems only 🙂