Google Photos is primarily an online experience, but you can take things offline for your own backup with Google Drive.
One of the best features of Google Photos is that you can access your pictures from any device that has a web browser or a Google Photos app, but the fact that it’s kind of a black box and you don’t know where exactly your photos are can be a little bothersome. Sure you can download copies of any photo you want from your library, but having an automatic local copy of photos as they are uploaded is even better.
With the Google Drive desktop app and a few tweaks you can have just that — we’ll show you how to set it up and a few of the limitations of the system.
Source: iMore
