The Schengen Agreement is a treaty between 26 European countries that enables the free movement of people within their borders. This agreement, which was signed in 1985 and came into effect in 1995, abolished internal borders, allowing for passport-free travel within the Schengen Area.

The Schengen Agreement is named after the town of Schengen in Luxembourg, where the agreement was signed. The treaty was originally signed by five European countries: Belgium, France, Germany, Luxembourg, and the Netherlands. Over the years, more countries have joined the agreement, and it currently includes 22 EU member states and four non-EU countries (Iceland, Liechtenstein, Norway, and Switzerland).

The Schengen Agreement is unique in that it is not an EU treaty but rather a standalone agreement among participating countries. However, the Schengen Area is closely tied to the European Union, as most of its member states are also EU members.

The primary goal of the Schengen Agreement is to facilitate the movement of people within the participating countries by eliminating internal borders and streamlining border controls. This has greatly simplified travel within the Schengen Area, making it easier for tourists, students, and workers to move from one country to another.

In addition to free movement, the Schengen Agreement also includes provisions for law enforcement cooperation and visa policy. Participating countries work together to fight cross-border crime and terrorism, and they maintain a shared visa policy for non-EU travelers.

While the Schengen Agreement has greatly facilitated travel and economic activity within the Schengen Area, it has also faced criticism and challenges. The 2015 migration crisis, which saw a large influx of refugees and migrants into Europe, put additional pressure on the Schengen Area and led to the reintroduction of border controls in some countries.

Despite these challenges, the Schengen Agreement remains an important pillar of European integration and cooperation. By enabling the free movement of people and fostering closer ties between participating countries, it has helped to bring Europe closer together and create a more unified, peaceful continent.