This article explains how to sync your iPhone and iPad using the iCloud service. Instructions apply to iPhones and iPads running iOS 11 and later.
How to Sync iPhone and iPad
If you want to keep the data on your iPhone and iPad in sync, use Apple iCloud to keep all your devices in sync at all times. As long as both devices are connected to the Internet and have the same iCloud settings, and you access them with the same Apple ID, they will stay in sync.
Here's how to set up iCloud:
On one device, open the Settings app, tap your name to open the Apple ID screen, then select iCloud.
