Lineage and clan are fundamental concepts in the study of kinship, both referring to groups of people who trace their descent from a common ancestor, but differing in their specificity and scale.

A lineage is a unilineal descent group (either patrilineal or matrilineal) whose members can trace their descent directly from a known, common ancestor through a specific line of males or females. The genealogical links are demonstrable and remembered by all members. Lineages are typically smaller, more cohesive, and often function as corporate groups, holding property, managing resources, and exercising political or ritual authority collectively. For example, all members of a patrilineage can name the male ancestors connecting them to the founding father.

A clan, in contrast, is a larger, more inclusive unilineal descent group whose members believe they are descended from a common, often mythical or remote, ancestor, but cannot necessarily demonstrate all the genealogical links. The descent is 'stipulated' rather than 'demonstrated.' Clans are often exogamous, meaning members must marry outside their clan, and may be associated with a totem (an animal, plant, or natural object). Clans provide a broader sense of identity and solidarity, often spanning multiple villages or regions, and play a role in regulating marriage and maintaining social order. While lineages are concrete and localized, clans are more abstract and dispersed, providing a wider network of affiliation.