The concrete social system of the Navajo is ordered by the conceptual or symbolic system. The central symbol of Navajo social organization is motherhood. The symbolic meaning of motherhood is found in life, reproduction, and subsistence. It is expressed in affectionate care and in the giving or providing of food. The basic unit of the concrete social system of the Navajo, the subsistence residential unit, is organized, structured, and integrated by the symbols of motherhood.