What exactly are visas and passports? How to say it in English?

Visa refers to the procedure of endorsement and seal of passports or other travel documents held by domestic or foreign citizens by the sovereign organs of a country 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 word Passport means port pass in English. In other words, a passport is a passport for citizens to pass through international ports in various countries. Therefore, some countries in the world usually issue passes instead of passports. 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.