A visa is an official document that allows the holder to officially pass in a foreign country. There are numerous different kinds of visas such as Travel/Tourist Visa, Business Visa, Work Visa, Student Visa and etc. that each one of these afford the holder different rights in the host country.
Schengen Visa is a short-stay visa that permit an individual to travel to any members of the Schengen area and per stays up to 90 days for tourism or business purposes. The Schengen visa is the most common visa for Europe and let its holder to go in, travel inside and leave the Schengen zone from any of the Schengen member countries without any border controls within the Schengen Zone. However, if you are scheduling to study, work, or live in one of the Schengen countries for more than 90 days, then you must apply for a national visa of that European country.