In anthropology, kinship is the web of social relationships that form an important part of the lives of all humans in all societies, although its exact meanings even within this discipline are often debated.
Anthropologist Robin Fox states that "the study of kinship is the study of what man does with these basic facts of life – mating, gestation, parenthood, socialization, siblingship etc." Human society is unique, he argues, in that we are "working with the same raw material as exists in the animal world, but [we] can conceptualize and categorize it to serve social ends." These social ends include the socialization of children and the formation of basic economic, political and religious groups.
As the basic unit for raising children, Anthropologists most generally classify family organization as matrifocal (a mother and her children); conjugal (a husband, his wife, and children; also called nuclear family); avuncular (a brother, his sister, and her children); or extended family in which parents and children co-reside with other members of one parent's family.
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, it is necessary for the formation of an economically productive household.
With matrilineal descent individuals belong to their mother's descent group.
Matrilineal descent includes the mother's brother, who in some societies may pass along inheritance to the sister's children or succession to a sister's son.
For example, the word brother in English-speaking societies indicates a son of one's same parent; thus, English-speaking societies use the word brother as a descriptive term referring to this relationship only.
In many other classificatory kinship terminologies, in contrast, a person's male first cousin ( whether mother's brother's son, mother's sister's son, father's brother's son, father's sister's son) may also be referred to as brothers.
When a descriptive terminology is used, a term refers to only one specific type of relationship, while a classificatory terminology groups many different types of relationships under one term.Different societies classify kinship relations differently and therefore use different systems of kinship terminology – for example some languages distinguish between affinal and consanguine uncles, whereas others have only one word to refer to both a father and his brothers.Kinship terminologies include the terms of address used in different languages or communities for different relatives and the terms of reference used to identify the relationship of these relatives to ego or to each other.Human kinship relations through marriage are commonly called "affinity" in contrast to the relationships that arise in one's group of origin, which may be called one's descent group.In some cultures, kinship relationships may be considered to extend out to people an individual has economic or political relationships with, or other forms of social connections.