C2 used to refer to plants and animals that grow naturally in a place, and have not been brought there from somewhere else:
Henderson Island in the Pacific has more than 55 species of native flowering plants.
The horse is not native to America - it was introduced by the Spanish.
B2 [before noun] relating to the first people to live in an area:
The Aborigines are the native inhabitants of Australia.
the native population
native customs and traditions