The Schengen countries are a united Europe

In 1985, a truly historic event occurred in the town of Schengen (Luxembourg). After a lengthy preparatory work, a document was signed that establishes certain relations between the five countries: Germany, France, Belgium, the Netherlands, the Great County of Luxembourg. The last three countries became the core of the Schengen agreement, since in 1921 they formed the customs and economic union of Benelux. Only ten years later, in March 1995, the Schengen Treaty became effective.

By agreement, the territories of these countries became the Schengen zone. The countries that are members of the Schengen zone do not have internal border control, but, as a single state, have border and visa control at the outer borders of the zone.
A Schengen visa issued by one of the countries under the above-mentioned treaty allows crossing the borders of the Schengen countries without visa problems for the traveler and temporary travelers.

But with police control or at the airport, the hotel requires the presentation of a passport or some other document certifying the identity of a citizen of a Member State of the European Union. Sometimes, due to any political events, control at the borders of the Schengen states is restored for a month, but no more.

The Schengen countries actively develop judicial and police cooperation, develop common rules for entry and stay of temporary visitors.

Currently, the Schengen zone includes 27 European countries. Plus de facto: micro-states of Monaco, the Vatican and San Marino. Andorra, not being a party to the Schengen agreement, has open borders with France and Spain.
Almost all countries of the Schengen Agreement are member countries of the European Union. Not included in the EU: Iceland, Switzerland, Norway and Liechtenstein, but they, according to the Amsterdam Treaty, since 1999 are part of the Schengen area.

The territory, which can be traveled without separate state visas, was developing gradually.

Nine states: Czech Republic, Hungary, Estonia, Lithuania, Latvia, Malta, Slovakia, Poland, Slovenia signed the Schengen agreement only in 2007. All of them are members of the European Union since 2004. At the same time Bulgaria, Cyprus and Romania were denied admission to the Schengen zone for various reasons. The decision on their accession is still postponed.

In 2008, Switzerland became a party to the Schengen Agreement, and in 2011 Liechtenstein became a participant. They entered the Schengen zone on the same terms as Iceland and Norway (non-EU members): these states are defined as bound by the Schengen obligations, the Schengen visa acts on their territories.

The Schengen zone is a territory of 4,312,099 square kilometers, in the "zone" there are more than 400 million people. That is, most of Europe is the Schengen area.

The countries of the Schengen Agreement are united by the legal framework of the single legislation. The Schengen area has common customs rules.
The agreement allows you to make business trips, travel, in general, to travel around Europe without visas to all citizens of the European Union. Citizens of states that are not members of this union, having received a visa from a country that is a member of the Schengen agreement, can also freely move around the Schengen area.

In fact, for a traveler or a business person with a Schengen visa, the Schengen countries become one huge country without borders, customs, and therefore without problems and complexities.

There are restrictions, so-called corridors - the terms in which the Schengen visa operates. In Germany and Italy, you can stay only 14 days, in Spain - 30 days, France allows you to stay 2 months, but Finland determines the visa corridor in a whole year.