What does restore from backup mean? It means that the backup file such as iTunes backup can be restored to your iPhone. After restore, all the data in the backup will be saved on your iPhone.
When you are in dire need of learning how to restore iPhone without passcode, this article solves your purpose.
Follow this article and learn how to restore iPad to factory settings in 4 ways: Settings, using iTunes, using iCloud or without iTunes/iCloud/passcode.