Family is a western term used to have denote a domestic group of people, or a number of domestic groups linked through descent (demonstrated or stipulated) from a common ancestor, marriage or adoption. A family may be defined specifically as a group of people affiliated by consanguinity, affinity, and co-residence. Although the concept of consanguinity originally referred to relations by blood, many anthropologists argue that the notion of "blood" must be understood metaphorically; some argue that there are many non-Western societies where family is understood through other concepts rather than "blood". Article 16(3) of the Universal Declaration of Human Rights says, "The family is the natural and fundamental group unit of society and is entitled to protection by society and the State".