I plan to not use an external SSD or HDD for backups. Floppies, CD's, DVDs, and now flash drives have done okay for me. So, it is a drag and drop command to get a "manual," copy made. My hand has trouble with drag and drop, so I was hoping there were menu selections in the OS to select a file or folder, then select copy to, then select the destination. Maybe Time Machine works like that a bit by clicking on commands instead of drag and drop. From what I've read about Time Machine, it seemed to be an automated back up utility to be run with each use of the computer, and may even require an SSB with the capacity of the internal SSD. From your description maybe it could be used as an any time you like backup utilities that allows you select even just one file to send to a USB C port, not some automated back up system, or maybe it does both.