A taxicab, also known as a taxi or a cab, is a type of vehicle for hire with a driver, used by a single passenger or small group of passengers, often for a non-shared ride.
A taxicab conveys passengers between locations of their choice.
This differs from other modes of public transport where the pick-up and drop-off locations are determined by the service provider, not by the passenger, although demand responsive transport and share taxis provide a hybrid bus/taxi mode.Źródło: https://en.wikipedia.org/wiki/Taxicab
This is because the employees of different companies need to move between the various branches, and many private individuals have family and friends even in the most remote parts of the world.
Therefore airports organize for its clients with different means of transport, which can be used both on the way to the airport and on the way from the airport to a private home or hotel.
Available airport transfers also create the opportunity to transport luggage or several people in one vehicle.
Information about such airport transfers can be found on the airport websites and on various boards of timetables.