A citizen is a full and equal member of a political community, such as a country or nation-state. Such membership is a necessary condition for the establishment and maintenance of a democracy. The citizens are “the people” to whom a democratic government is accountable.
In most countries, the status of a natural citizen is derived primarily or even exclusively from one’s parents; if the parents are citizens, then their children automatically become citizens. If one does not have a birthright to citizenship either through one’s parents or place of birth, there usually are legal procedures by which a person can become a naturalized citizen of a country. A country’s constitution and the laws based on it specify the means for obtaining the status of citizen. For example, the 14th Amendment of the U.S. Constitution says, “All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside.”
In a democracy, all citizens, both natural and naturalized, are equal before the law and have the same fundamental rights, duties, and responsibilities.
All citizens have a common civic identity based on their freely given consent to basic principles and values of their country’s constitutional democracy. In countries with great religious, racial, or ethnic diversity, a common civic identity among all citizens is the tie that binds them together under their constitutional and democratic government.
A passport is evidence of a person’s status as a citizen of a particular nation. A citizen of one country usually needs a passport to enter and depart legally from another country.
John Patrick, Understanding Democracy, A Hip Pocket Guide