Dual passport

A passport is a travel document, usually issued by a country's government, that certifies the identity and nationality of its holder primarily for the purpose of international travel. Standard passports may contain information such as the holder's name, place and date of birth, photograph, signature, and other identifying information. Many countries are moving towards including biometric information in a microchip embedded in the passport, making them machine-readable and difficult to counterfeit. As of December 2008, 60 countries were issuing biometric passports, and this number was 96 as at 5 April 2017. Previously issued passwords usually remain valid until each expires.

A passport holder is normally entitled to enter the country that issued the passport, though some people entitled to a passport may not be full citizens with right of abode. A passport does not of itself create any rights in the country being visited or obligate the issue country in any way, such as providing consular assistance. Some passports attest to status as a diplomat or other official, entitled to rights and privileges such as immunity from arrest or prosecution.

Many countries normally allow entry to holders of passports of other countries, sometimes requiring a visa also to be obtained, but this is not an automatic right. Many other additional conditions, such as not being likely to become a public charge for financial or other reasons, and the holder not having been convicted of a crime, may apply. Where a country does not recognise another, or is in dispute with it, it may prohibit the use of their passport for travel to that other country, or may prohibit entry to holders of that other country's passports, and sometimes to others who have, for example, visited the other country.

...
Wikipedia