Family denotes a group of people affiliated by consanguinity, affinity, or co-residence. Although the concept of consanguinity originally referred to relations by "blood," many anthropologists have argued that one must understand the notion of "blood" metaphorically, and that many societies understand 'family' through other concepts rather than through genetic distance.

Many sociologists and anthropologists believe the primary function of the family is to perpetuate society, either biologically, socially, or both. Thus, one's experience of one's family shifts over time. From the perspective of children, the family is a family of orientation: the family serves to locate children socially, and plays a major role in their enculturation and socialization. From the point of view of the parent(s), the family is a family of procreation the goal of which is to produce and enculturate and socialize children. However, producing children is not the only function of the family; in societies with a sexual division of labor, marriage, and the resulting relationship between two people, is necessary for the formation of an economically productive household.

A conjugal family consists of one or more mothers and their children, and/or one or more spouses, usually husbands. The most common form of this family in the western world is regularly referred to as a nuclear family.

A consanguineal family consists of a mother and her children, and other people — usually the family of the mother, like her husband. This kind of family is common where mothers do not have the resources to rear their children on their own, and especially where property is inherited. When important property is owned by men, consanguineal families commonly consist of a husband and wife, their children and other members of the husband's family.

A matrifocal family consists of a mother and her children. Generally, these children are her biological offspring, although adoption of children is a practice in nearly every society. This kind of family is common where women have the resources to rear their children by themselves, or where men are more mobile than women.

Economic functions

Anthropologists have often supposed that the family in a traditional society forms the primary economic unit. This economic role has gradually diminished in modern times, and in societies like the United States it has become much smaller — except in certain sectors such as agriculture and in a few upper class families. In China the family as an economic unit still plays a strong role in the countryside. However, the relations between the economic role of the family, its socio-economic mode of production and cultural values remain highly complex.