iOS backups
It’s worth noting that iCloud isn’t a backup service — the box on this page tells you why — but it is a useful way of backing up your iPhone, iPad, iPod touch, or Apple Watch automatically. Those backups are particularly handy if you’re resetting one of your devices or upgrading to a newer model; all of its app details, logins, and settings are stored in iCloud, so you can restore them or transfer them to your new device.