Wikipedia--Multiple Citizenship

Multiple citizenship is a status in which a person is concurrently regarded as a citizen under the laws of more than one state. Multiple citizenships exist because different countries use different, and not necessarily mutually exclusive, citizenship requirements. Colloquial speech refers to people "holding" multiple citizenship but technically each nation is making a claim that this person be considered its national. For this reason it is possible that a person be a citizen of one, none or many countries. more