Officially, Google has ended its Google Photos Backup service. It has been replaced with Google Backup and Sync. Although, the transition from Google Photos Backup to Google Backup and Sync has been going on for a while, it's only until recently that the service was discontinued.
What you need to know
1. This only affects your computer, not your mobile devices. Backup and Sync is the desktop software that will automatically upload photos from your computer’s drives to your Google account in the cloud.
2. You only need this if you have a lot of photos on your computer. If you just have a few, it is easy to manually upload them to your Google Photos account, don’t bother with Backup and Sync. If you have been using Google Photos backup (aka Desktop Uploader) then all your current photos are already uploaded. My advice would be to discontinue any automatic uploading and use the easy manual methods from now on.
3. If you do have thousands of pictures on your computer that you want uploaded to your Google Photos account, then you want the free piece of software called Google Backup and Sync. It replaces the older free software called Google Photos Backup. Now that Picasa’s uploading capability has been removed, Backup and Sync is your only automatic option.
4. The biggest difference between the old Google Photos Backup and the new Backup and Sync is that Backup and Sync is not just for Google Photos, it is primarily a Google Drive utility. Any files uploaded will go to Google Drive, they will also go to Google Photos if you check the box to upload to Google Photos. You can choose to upload at High Resolution to avoid using up any of your storage allotment even on Google Drive. Also, the new software will Sync, not just Backup. That means that you can also set it up to download your Google Photos pictures to your computer.