How does the mobile operator determine which app I'm using?

Question

mobile connection

Good afternoon, the following question arose:
How do mobile operators understand which application I use? That is, for example, I have 1 GB of Internet for a month, and if I use up this reserve, then I will no longer be able to access the Internet, but at the same time, if my tariff plan implies unlimited, for example, for some Instagram, then regardless of whether I have free MB or not, I will be able to scroll through the feed on Insta. And actually the main question is how mobile operators determine which application I use and is it possible to somehow "slip" false information about the current application to the operator?

Answer 1

They define addresses and not applications. As well as staff stores