What is a "private transfer" as it relates to traveling? [closed]

In the airport context, it could also mean a chauffeured car/shuttle that is not registered as a taxi (and therefore cannot wait in the area designated for taxis). I would be curious to know where you read that however as I would generally question the recommendation. If you have the means for it and don't want any hassle, taxi is fine but generally speaking public transport is also very good at many European airports.

"Private" just refers to the fact that you will be doing business with a private organization rather than a public one (i.e. the government).

This generally refers to taxi cabs and shuttles, which are run by specific companies (private) as opposed to things like buses and trams which are generally run by the city (public).

So, in your example, people are basically recommending that you call a taxi rather than try to take a bus.