When you enable or turn on iCloud Photo library on all your devices, all the photos and videos in your photo library are stored in iCloud, so you can access them from your Mac, PC, iOS devices, Apple TV, and on iCloud.com.
Any new photos you add to Photos or take with an iOS device appear on all your devices that have iCloud Photo Library turned on. Your photos and albums are organized the same way on every device, and if you make edits, you see your changes on all your devices. Your original, full-resolution photos and videos are stored in iCloud, and you can keep smaller versions on your Mac to optimize storage.
Set up iCloud Photo library on all your accounts.