iCloud Photos
The ins and outs of the iCloud service you’ll use most
What about iMessage?
> If you have Messages in iCloud enabled (it’s in Messages > Preferences > iMessage on your Mac), it doesn’t just keep your messages in sync between your devices. Apple will store your entire message history in iCloud, including any photos or other attached files. It’s worth going into Settings > iCloud > iCloud Storage and having a clear-out from time to time: if you’re an avid Messages user, your accumulated reaction GIFs and cat videos can take up a big chunk of your iCloud storage.
iCloud Photos (formerly iCloud Photo Library) automatically copies any photos or videos you take on your devices and stores them in iCloud. You can then access them on your other Apple devices or share them with others. It supports the most common photo and video formats including Apple’s favoured HEIF (High Efficiency Image Format) and HEVC (High Efficiency Video Codec) formats and the standard JPEG, RAW, PNG, TIFF, MP4 and GIFs used by most image apps. It integrates seamlessly with your Photos app (and the data it syncs includes your People album, which is the one that uses image recognition to recognise people in your photos), and you can also access your library from any web browser via iCloud.com.