What does this sentence mean? Virtually no part of excel is easily auditable, at best you can see "this file was changed by xyz at a:b:c" identifying the cells that have changed between versions wouldn't even be easy.
It lists side-by-side differences in hardcoded values, formula changes, calculated value changes, and even changes in VBA code. The list of changes can then be dumped out to a text file.
Default Excel installations also include the Inquire add-in which allows you to perform the comparison within Excel itself.
[0] https://support.microsoft.com/en-us/office/compare-two-versi...