How to save to icloud

Save what to iCloud exactly?

On iPhone and iPad, things like Contacts, Notes, Calendar save by default to iCloud if the option is turned on in Settings ➜ Account (top of Settings) ➜ iCloud ➜ Apps Using iCloud ➜ Show All.

For Photos, you can turn on the iCloud Photos option in Settings ➜ Photos.

For Files, you can move files in the Files app, to the iCloud Drive location.

For backups, unless you turn off the option, the iPhone should automatically backup to iCloud when its screen is turned off, and its connected to power and Wi-Fi for an extended period of time, like over night.

Settings ➜ Account ➜ iCloud ➜ iCloud Backup

click here ➜ Use iCloud on iPhone - Apple Support

Settings > [Tap your name] > iCloud > Photos > iCloud Photos [Enable]

Now you can see it on https://www.icloud.com/photos from any web browser and all other devices which is logged in with the same Apple ID.

If you enable iCloud for Photos / Notes / Videos / Reminders / Messages etc (As Shown in the Pic below) and have deleted some or all data from one device then it is deleted from iCloud and all other devices that is logged in with the same Apple ID.