Mac OSX...
* Time Machine creates backups of entire disks. After the first backup it adds incremental changes (automatically if backup disk is connected and running). Time Machine program displays entire timeline of backup copies for you to examine and search.
* The resource fork of a file contains information about it. There are utility programs for reading it, although the format has changed over the decades.
* Open "Get Info" of any file (or folder) to view facts about it. The Comments window is available for any and all purposes.
* Include revision date in the filename when you save it. Then a disk search might locate it more easily.
* In Finder open 'Show View Options' to choose which facts are displayed about files (creation date, modified date, last opened).