Firstly, Schengen visas are short-term visas that allow their holder to travel throughout the Schengen area. They allow their holder to enter, freely travel within, and exit the Schengen zone from any Schengen member country. That is to say, there are no border restrictions within the Schengen Zone. The Schengen area includes 26 nations (“Schengen States”) with no border controls. For instance, Austria, Belgium, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, and Switzerland are among these countries.

Secondly, it is an authorization granted by a Schengen State to:

A planned stay in the territory of the Schengen States for no more than 90 days in any 180-day period (“short stay visa”).
A transit via the international transit areas of Schengen airports (“airport transit visa”).
However, If you intend to study, work, or live in one of the Schengen countries for more than 90 days, you must apply for a national visa of that European country rather than a Schengen Visa.