Schengen Zone consists of 26 European countries which have signed the agreement that guarantees abolishment of their internal borders, free movement of people, capital, services, and goods. These nations are nearly 420 million European people.
Schengen countries have also established common policy concerning insurance obligations for outside Schengen visitors. These requirements are identical in whole Schengen Zone of 26 European countries.
However, European Union countries list is the same in a significant part, but don't confuse it with the list of the countries of Schengen Area: