From The Apple Wiki

What is it? represents a property list file holding the settings for the as well as Springboard on iOS. The file is present on all iOS devices and holds the progress of the Setup so that the phone knows if you already selected a language, a country, a Wi-Fi Network, if you already signed into your iCloud ID and any other variable that might occur in

Where is it?

The position of the settings file is /var/mobile/Library/Preferences/

What happens if I remove it?

It might trigger the again (this one will create the file again).