A visa is official permission from a country that allows a person to enter, stay, transit, study, work, or visit under specific rules. The type of visa determines what the person is allowed to do.
What a visa can include
A visa may include validity dates, number of entries, length of stay, allowed purpose, and conditions. Some visas are stamped or attached to a passport, while others are electronic.
Visa versus passport
A passport is issued by the traveler's own government as identity and travel proof. A visa is permission from the destination country.
Visa rules vary widely, so travelers must check the rules for their destination and passport nationality.