The airport transit visa allows holders to pass through the international transit area of a Schengen airport during a stop-over or transfer between two stages of an international flight. The holder does so without actually entering the national territory of the country.
Nationals of the following countries require an airport transit visa to transit through a Schengen airport: Afghanistan, Bangladesh, Congo (The Democratic Republic), Eritrea, Ethiopia, Ghana, Iran, Iraq, Nigeria, Pakistan, Somalia and Sri Lanka, unless they are residents of an EU member state, an EEA country, USA or Canada with permission to return at least 90 days after transiting the Schengen area.
Please note that Norway does not recognize transit visas, therefore a Schengen visa is required to transit through Norway.
Passports are not checked on flights when travelling within the Schengen area. If you have two or more stopovers in the Schengen area, you will be required to leave the international transit area and pass through the border checkpoint in order to catch your next flight within Schengen. The same applies if your itinerary requires you to change airports.