Use these steps if you have a new iOS device, or you need to to restore after a factory reset:
1. Turn on your device. You should see a Hello screen.
2. Follow the steps in the iOS Setup Assistant until you reach the Apps & Data screen, then tap Restore from iCloud Backup.
3. Sign in with your Apple ID, then choose a backup.
Stay connected and wait for a progress bar to appear and complete. Depending on the size of the backup and the network speed, the progress bar might need a few minutes to an hour to complete. If you disconnect from Wi-Fi too soon, the progress will pause until you reconnect.
Now you can finish setup and enjoy your device. Content like your apps, photos, music, and other information will continue to restore in the background for the next several hours or days, depending on the amount of information there is. Try to connect often to Wi-Fi and power to let the process complete.
To restore using iTunes, go to support.apple.com/ht204184.