Finding a good free backup solution is easier than you’d think. A host of companies offer free online backup or free backup software—and perhaps surprisingly, nearly all of them are quite competent.

Of course these companies have ulterior motives. Their free versions usually provide only enough storage for essential data, or lack some advanced features that pros would want. They hope you’ll love the program or service so much, or find it so useful that you’ll eventually fork over some cash for additional storage or advanced features. 

But wait, you say: I have free online storage through Apple’s iCloud or Google Drive, or Microsoft OneDrive. Then there are services like Dropbox, with 2GB for free.

The issue with all those services is that they’re not necessarily true backup, but syncing. That is, when you delete a file from any device or online, it’s deleted from every device. Lord help you if you make a mistake and don’t realize it in time. True backup means retaining data indefinitely no matter what’s happening with the data elsewhere.

https://www.pcworld.com/article/407569/the-best-free-backup-software-and-services.html