What does GFI mean or stand for ?

Ionization is the process of subjecting a electric current to either a solid or a gaseous environment and thereby creating an emitting stream of ions.These ions are the same atoms of the Gas/Solid that have now become either electrically/positively charged.

GFI is the process of passing an electric current through a field of gas.This electrifying current that creates gas ions is known as Gas field Ionization.