This lecture discusses definitions of indigenous peoples. It explains that indigenous peoples are typically defined as having ancestral roots in a given territory, maintaining distinct cultural and social identities and forms of social organization. The lecture outlines several common elements used to define indigenous groups, including self-identification, ancestral descent, historical continuity of culture and language, occupation of ancestral lands, distinct lifestyle and aspiration for self-preservation. Providing a clear definition of indigenous peoples is important to protect their rights and assert their claims to lands and self-determination under international law.