Descent groups are fundamental social units in many societies, comprising individuals who trace their ancestry to a common progenitor. They play a crucial role in organizing social, economic, political, and ritual life, often determining inheritance, marriage patterns, residence, and group identity.

There are several types of descent groups:

1. Unilineal Descent: This is the most common form, where descent is traced exclusively through either the mother's or the father's line.

   • Patrilineal Descent: Individuals trace their ancestry through their father's line. Children belong to their father's descent group. This is common in societies where men hold significant economic and political power.
   • Matrilineal Descent: Individuals trace their ancestry through their mother's line. Children belong to their mother's descent group. While less common than patrilineal, it is found in various societies, often where women have significant roles in resource control or production.

2. Bilateral (Cognatic) Descent: In this system, individuals trace descent through both the mother's and the father's lines, recognizing relatives on both sides. This is characteristic of many Western societies, where kinship is often more flexible and less rigidly structured into corporate groups.

3. Ambilineal Descent: A flexible form of unilineal descent where individuals can choose to affiliate with either their mother's or father's descent group, or sometimes both, depending on various factors like residence or inheritance.

Descent groups often form corporate units, meaning they own property, manage resources, and act collectively. They provide a sense of belonging, mutual support, and continuity across generations, reinforcing social cohesion and cultural norms.