"To create a backup" means making a copy or a duplicate of something important, like files or data, in case the original gets lost, damaged, or deleted.
Sentences with «to create a backup»
I have never heard of anyone creating a backup of a system drive on the system drive itself. (thewindowsclub.com)
Make sure to create backups for all the files before starting the installation of such file on your tablet. (android.gs)
This easy cheat mode procedure involves editing a game file, so create a backup copy of the file before proceeding. (lifewire.com)