One of the primary functions of the family involves providing a framework for the production and reproduction of persons biologically and socially. This can occur through the sharing of material substances (such as food); the giving and receiving of care and nurture (nurture kinship); jural rights and obligations; and moral and sentimental ties. 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, 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, it is necessary for the formation of an economically productive household.