3 - 2 - 1 is the magic formula for keeping your data safe against most ways of losing it. 3 copies in 2 locations of 1 file. Unfortunately, most people only have a 2 - 1 solution. 2 copies of 1 file.
For the longest time I've just kept my photos in the Google Photos app on my phone and on Google's servers. It's two copies in two locations.
Photo Sync adds a third copy to your photos by staying constantly in sync with your Google Photos and downloading your newest snaps to your laptop or desktop hard drive. It's literally the only job it has - making sure that your photos are always in sync.
Simply download the app, install it and log in with your Google account to get started.
A download of Photo Takeout