Unilineality is a system of determining descent groups in which one belongs to one's father's or mother's line, whereby one's descent is traced either exclusively through male ancestors (patriline), or exclusively through female ancestors (matriline). Both patrilineality and matrilineality are types of unilineal descent. The main types of the unilineal descent groups are lineages and clans.
A lineage is a unilineal descent group that can demonstrate their common descent from a known apical ancestor