What happens if the phone is restored to factory settings? Phone book, SMS, MMS, documents?

Phone book, SMS and MMS will not exist after the phone is restored to the factory settings, because these things are stored in the phone memory, and the phone system will be automatically erased when it is restored to the factory. However, your documents and materials are generally stored in the SD card, so they are not affected. Of course, you must make sure that your documents and materials are stored in the card. Otherwise, you must back up the phone book, SMS, MMS and documents before restoring the factory settings.