A passport is an official document issued by a government. It identifies the holder and is commonly required for international travel.
What a passport contains
A passport usually includes the holder's name, photo, date of birth, nationality, passport number, issue date, expiration date, and issuing authority.
Passport versus visa
A passport identifies the traveler. A visa is permission from a destination country to enter, stay, work, study, or transit under certain rules.
A passport does not automatically guarantee entry into another country, but it is the core international travel document.