Off topic backup query

[Bill Troop <billtroop@xxxxxxxxx>]

Recently I changed my cloud backup from Memopal to iDrive. 

The great thing about Memopal for me was that it kept endless copies of a
file. So if there was a corruption issue and you had to go back to a file
that was backed up an hour ago rather than half an hour ago, they would
both be there. 

WHAT is this kind of backup called, where you have infinite copies
of a file, and every now and then have to prune some of them out because
they are taking up so much space?

My new cloud backup doesn't do that. It always overwrites the previous
instance of the file. And it so happens that I just had a very rare
indeed instance of minor corruption in a Eudora file, following a Win 10
crash caused by Chrome, and could not access a useful backup file.
(iDrive does do a lot of things that Memopal doesn't - - that, and
economy, is why I switched.)

Any recommendations? 

For hard disk backup/imaging I still use a program Ed recommended many
years ago, ShadowProtect (which I found much superior to Acronis). But I
don't use it very often, and it wasn't able to help me in this case, and
it doesn't do this multiple-copies-of-a-file type of backup. 

For the Mac, I haven't yet set up time machine (not ever having found,
historically, that Apple-supplied backup was reliable) but I understand
that it does keep previous revisions of a file. so that would be good for
me on that platform. That leaves the problem of what to do on Windows.