The relationship between passport and visa
Passport is a legal document issued by a country to prove the nationality and identity of its citizens when they enter and leave the country and travel or stay abroad. The word passport means port pass in English. In other words, a passport is a passport for citizens to pass through international ports. Therefore, some countries in the world usually issue passes instead of passports.
Visa (avisa) refers to the procedure that a country's sovereign organs endorse and seal passports or other travel documents held by its own or foreign citizens to show that they are allowed to enter, exit or transit. It can also be said that it is an endorsement certificate issued to them. Generally speaking, a visa is a document issued by a country's entry-exit administration (such as immigration bureau or its embassy or consulate abroad) to approve the entry of foreign citizens.
The popular understanding is that a passport is equivalent to an ID card and a visa is equivalent to a passport. Passport is a book, and you must put a visa on it to successfully complete the exit formalities.