Best practices often suggest you should have 3 different copies of your files on 2 different types of media. Photonix software can be used in a few different ways.
If you are only going to run it so that it’s image files are stored on the same hard drive as you usually use, then it can’t offer any kind of backup.
If you are going to setup a home server and install Photonix on it in a way that copies files onto it’s hard drive whilst leaving the original versions on the original computer, then that will give you one backup. This will save you when one of the hard drives fail but if they’re both in the same location then it doesn’t offer anything in cases like flooding, fire and theft.
An upcoming feature will allow you to use cloud storage to store your pictures. This will provide you with safe storage in an off-site location and you you’ll be able to grow the size of your library without purchasing hard drives upfront.