Do I sound a little redundant? That is precisely the point. You need to backup with redundancy. If your home computer holds your children’s baby pictures, important documents, etc. then I am assuming you wouldn’t want to lose them?
There are lots of ways to backup. I backup my computer to an external hard drive, but also to a cloud service (currently Carbonite). I also backup my photos to Amazon Prime photos (it’s free with your Prime membership) and Google photos (which is also free). Yes, all of those places.
I have met with clients in tears because their computer died and they hadn’t backed up. It can be devastating.
Apple computers have a built in software, Time Machine, that does a great job of backing up all of your data (including programs). Windows also has a built in backup.
Once you have set up your backup, that’s great! You are off to a good start. Don’t stop there. Once a week (or once a month) … try and restore a file. Make sure your backups are working.