One way is simply to copy files to a backup drive - for example an external USB drive (I use Western Digital MyBooks).

The intent is that you’re protecting your valuable data from the possibility of loss, though that possibility may be small.

It pays to take some time to understand your backup system and what you’ll need to do to restore files, since when you need it it’s never convenient, and you’ll be without your computer system with which you could have done the research.

-Noel