dual citizenship

Multiple citizenship, dual citizenship, multiple nationality or dual nationality, is a person's citizenship status, in which a person is concurrently regarded as a citizen of more than one country under the laws of those countries. Conceptually, citizenship is focused on the internal political life of the country and nationality is a matter of international dealings. There is no international convention which determines the nationality or citizenship status of a person. This is defined exclusively by national laws, which can vary and conflict with each other. Multiple citizenship arises because different countries use different, and not necessarily mutually exclusive, criteria for citizenship. Colloquially, people may "hold" multiple citizenship but, technically, each nation makes a claim that a particular person is considered its national.
A person holding multiple citizenship is, generally, entitled to the rights of citizenship in each country whose citizenship he or she is holding (such as right to a passport, right to enter the country, right to residence and work, right to vote, etc.), but may also be subject to obligations of citizenship (such as a potential obligation for national service, becoming subject to taxation on worldwide income, etc.).
Some countries do not permit dual citizenship or only do in certain cases (e.g. inheriting multiple nationalities at birth). This may be by requiring an applicant for naturalization to renounce all existing citizenship, or by withdrawing its citizenship from someone who voluntarily acquires another citizenship, or by other devices. Some countries permit a renunciation of citizenship, while others do not. Some countries permit a general dual citizenship while others permit dual citizenship but only of a limited number of countries.
A country that allows dual citizenship may still not recognize the other citizenship of its nationals within its own territory (for example, in relation to entry into the country, national service, duty to vote, etc.). Similarly, it may not permit consular access by another country for a person who is also its national. Some countries prohibit dual citizenship holders from serving in their armed forces or on police forces or holding certain public offices.

View More On Wikipedia.org