...The purpose of the file hash comparison is to identify files whose contents have changed. For example, the files on an up-to-date data drive may be compared against the files previously found on that data drive, or on a backup drive.
Identifying changed files may be useful as a precaution against ransomware. The Support tab (above) links to a blog post discussing uses of the spreadsheet for that purpose. See also https://raywoodcockslatest.wordpress.com/2022/04/10/ransomware-spreadsheet/