What is the plastic film covering on a cigarette pack?

There is nothing in the world called stylophane, this material is not an existing one. That's what people around me have always called it. But I want to know what the plastic film outside a cigarette pack is. I'm guessing it's probably a biodegradable biopolymer. Anyone know?|||It used to be called cellophane, I've never heard the term 'stylophane' before. No idea what the current material is.