Today Google Photos is ending their free unlimited storage for 'high-quality' or compressed photos. What does this mean for you? Google Photos will still offer 15GB of free storage. If you have a Pixel phone you will still have unlimited 'Google Photos' storage. Now is a good time to check and see if you have Google Photos 'back up and sync' The current photos you have saved will not count against the new 15GB policy. You have other options for cloud services, Google also offers larger storage for a small monthly fee.
Techradar has more details and other options here.