Armenian nationality law is regulated by the Constitution of Armenia, as amended; the Citizenship Law of Armenia and its revisions; and various international agreements to which the country is a signatory. These laws determine who is, or is eligible to be, an Armenian national. The legal means to acquire nationality, formal legal membership in a nation, differ from the domestic relationship of rights and obligations between a national and the nation, known as citizenship. Nationality describes the relationship of an individual to the state under international law, whereas citizenship is the domestic relationship of an individual within the nation. Some countries use the terms nationality and citizenship as synonyms, despite their legal distinction and the fact that they are regulated by different governmental administrative bodies. In Armenia, colloquially the term for citizenship, "քաղաքացիություն", refers to both belonging and rights within the nation and the term for nationality, "ազգություն", refers to ethnic identity. Armenian nationality is typically obtained under the principal of jus sanguinis, i.e. by birth to parents with Armenian nationality. It can be granted to persons with an affiliation to the country, or to a permanent resident who has lived in the country for a given period of time through naturalization. Nationality in Armemia is typically acquired by birth to an Armenian or later in life through naturalization. Those who can acquire nationality by birth include: Children born anywhere when both parents are Armenian nationals; Children born to one parent who is Armenian, if the other parent is stateless or unknown; Children born to one parent who is Armenian, but whose other parent has a different nationality, by mutual written agreement of the parents; Children born in the territory of Armenia who would otherwise be stateless; or Foundlings or orphans discovered in Armenia whose parents are unknown. Naturalization in Armenia may be granted to persons who are of the age of majority (18) and have legal capacity.