It depends what phone it is
hard reset cricket domino
How to reset cricket a210 phone
How to factory reset ztex500m
Motorola l6 factory reset
To reset the Cricket EC1705 modem, locate the reset button, usually found on the back or bottom of the device. Use a pin or a paperclip to press and hold the reset button for about 10-15 seconds until the lights on the modem blink, indicating it is resetting. Release the button and allow the modem to reboot completely. Once the lights stabilize, the modem will be restored to factory settings.
Applications get erased when you do a factory reset.
germany
No, even if you factory reset the Galaxy S4 it will not downgrade.
If you do a factory reset then yes you will loose everything.
Resetting a rooted phone back to factory setting can be easy. All you have to do is go to the settings and click on the factory reset.
you cant
To reset your Galaxy S3, you simply need to: Launch settings, Open "Backup and reset," and tap "Factory data reset" to reset your galaxy s3 to its original factory settings.