Which StarCraft race is native to the planet Aiur?

The Protoss are the StarCraft race native to the planet Aiur.

Aiur is the Protoss homeworld and the center of their ancient civilization. The Protoss are technologically advanced beings with powerful psionic abilities, robotic support units, and a society shaped by traditions such as the Khala. Their homeworld is also central to the original StarCraft story, when the Zerg invasion forces the Protoss into a desperate defense.

Terrans are human descendants living in the Koprulu Sector, while the Zerg originate elsewhere and spread through infestation. A common mix-up is treating Aiur as the capital of every Protoss faction: it is the ancestral homeworld, but individual Protoss groups and exiles have operated from other locations, including Shakuras.