Kurdish kin groups are based on patrilineal descent. Several generations of one man's descendants through the male line constitute a lineage. Several such lineages compose a clan. It is assumed that all members of a clan are related through a common male ancestor, but outside groups may attach themselves to a powerful tribe and, after several generations, be incorporated as full members into a clan and tribe. A tribe consists of several clans.
Kurdish kinship terminology does not distinguish between maternal and paternal grandparents. It does distinguish between father's and mother's brothers, and between their children. Father's sisters and mother's sisters, however, are categorized together, as are their children.