You'll need a back up program of some kind.  I use Carbonite.

If you subscribe to your own cloud storage already, you can use various types of reputable programs that work with the protocol your cloud storage supports and which should, ideally, allow you to encrypt your data with your own key as an added layer of security (and yes, I'm fine being called a paranoid 😈).  We use GoodSync.

Carbonite has saved my butt many times!