Every so often you may come across a problem on your iPhone that is just too hard to fix, or maybe you want to give your phone to someone else and want to remove all your data before you do so.
To do this, you’ll need to restore your iPhone’s factory settings so it’s like you’re getting a brand new phone – and iTunes makes this easy to do.
To restore the settings, plug in the phone to your computer, and open iTunes – then click over to the iPhone summary screen.
In the middle of the screen, you should see an option to hit “Restore”. Doing so will completely wipe all your data. It’ll take a few minutes, but once you’re done, you’ll be able to set up your new phone as if it’s completely new.