Indigenous people are the original people who lived in a region, before immigrants. Indigenous people are also called aborigines, native people, first people, first nations, and autochthonous.
The United Nations likes to use the phrase Indigenous peoples because other phrases may sound bad (this is called a pejorative).
Many indigenous people were oppressed in colonial times. They were treated very poorly. Colonial settlers often robbed the indigenous treasures and took their lands. Sometimes indigenous people were made slaves, or killed by colonial settlers.