Roughly the same as the difference between a country and a business.

not really

Why not? The Vatican is its own country (and throughout history more a "real" country with lots of ordinary people living inside its borders).

Yes, the Papal States (the state that the Pope ruled over between ~800 and 1870) were to a large extent the successor to the Exarchate of Ravenna, the area that the Byzantine Empire reconquered in Italy from the mid-500s to the mid-700s. Ravenna had become the capital of the Western Roman Empire long before the fall of the Western Roman Empire, since it was closer to the action on the frontiers of Central and Eastern Europe.

maybe historically, but the Vatican is barely a country. if it had any citizens beyond employees of the institution maybe it could count as a coontry

You’re the one who picked the only church that has its own country. Don’t shoot the messenger.

so does disney. it's irrelevant. neither of them have any real citizens other than employees of the institution.

a church is a completely different institution to a country. countries are not decentralised. they do not advertise. they are (usually) not selling an idea. you cannot just decide to become a member of a country. the catholic church is all of those things and so are businesses. the catholic church is essentially a very entrenched business with a weak facade of being a state.

maybe in terms of scale they're similar to a state, but then how many people do the biggest businesses have as customers? billions?

A business generally don’t threat its audience with post-life infinite burn in Hell if they don’t buy its product. Also they don’t impose celibacy to their employees. Oh, and tax exemptions, I guess.

Yeah, modern corporations tend to threat people with things like raising sea levels to make them buy electric cars or photovoltaic panels, or vegan food. They also impose their woke worldviews on their employees. And don't get me started on tax exemptions.

No, those threats come from scientists, the companies just change their products over time to give people those options.