Can you reinstall OS without wiping?

[taptic]

I understand that you can wipe a computer and then install a fresh operating system and restore a backup. I was wondering however, can you reinstall OS X or macOS on top of existing data without removing it?

 

[jbarley]

No experience with macOS but with OS X the answer is Yes you can.

 

[Gjwilly]

I just installed Sierra over Sierra about two weeks ago.