A Factory Reset will WIPE all data on your iOS device.
Please ensure that you have backed up your device and understand that you will lose all your data before continuing.
Looking for a different reset option or more information? Refer to this article about the types of reset options.
From the home screen select Settings
Scroll down and select Reset
Select Erase All Content and Settings
Select Erase Now
Enter your passcode
Select Erase iPhone
You may also need to enter your Apple ID password to confirm device wipe.