Are passports divided into nationalities?

No, you need a visa even if you have a passport. That is, which country do you want to go to and need a visa. If you have a passport.

Passport is your entry and exit document, and it is your identification in China and abroad.

Passport is the holder's nationality and identity certificate, and visa is the permission certificate of a sovereign country to allow foreign citizens or their own citizens to enter, exit or transit.

Visas are generally endorsed on passports, some are endorsed on other travel documents instead of passports, and some are issued separately. For example, immigration visas in the United States and Canada are A4 paper, and Singapore also issues separate paper visas to foreigners. Generally speaking, a visa must be used at the same time as a passport to be valid.