The Zonai are a race that appears in Tears of the Kingdom.
Breath of the Wild
While no Zonai are seen in Breath of the Wild, the remains of Zonai buildings can be seen in two sets of ruins - the eponymous Zonai Ruins in Faron, and the Thyphlo Ruins in the Great Hyrule Forest, although the latter are covered in a permanent shroud of darkness which makes them hard to observe at length.
Tears of the Kingdom
Zonai are a race of humanoids. As the only two Zonai seen - Rauru and Mineru - are siblings, it is hard to say how "typical" they are, but both are tall and grey-skinned. While they are human-like from the neck down, their heads are very different, with animal-like noses and a third eye in the middle of the forehead, which they usually keep shut (As part of Rauru's court, Rauru's Hylian wife Queen Sonia and the time-travelling Princess Zelda wear tiaras which echo this third eye). They also have very large, pointed ears - Mineru generally holds hers pointing upward, while Rauru's - perhaps weighed down by his ten earrings - are held horizontally. Rauru has four small horns on his upper forehead, which Mineru does not possess, and has very long hair cascading down his back; while she keeps her hair short.
The Zonai had advanced technology, creating various Constructs that can still be found in the present across the Sky Islands. They range from Steward Constructs, who perform certain tasks, to Soldier Constructs who attack outsiders, and to various others that mine, create meals, and chop down trees. They also developed many Zonai Devices, which allow the user to make difficult tasks much easier. With these Devices, various transportation methods can be created, such as Carts, Sleds, and Wings for flying.
Long ago, the Zonai descended to Hyrule as godlike creatures, with Secret Stones that enhanced their powerful abilities. Rauru, the leader of the Zonai, met the Hylian priestess Sonia and married. The two became the first King and Queen of Hyrule, and established the Hyrule Kingdom. By this time, the only remaining Zonai were Rauru and his sister Mineru.
As an effect of the Upheaval, Zelda is transported to the past, where she first meets Rauru and Sonia. Zelda is told that she posseses power over time and power over light, which she inherited from Rauru and Sonia. Mineru and Sonia attempted to use their knowledge to return Zelda to her own era, but were unable to do so.
Ganondorf soon became a threat to Hyrule, sending a Molduga swarm to attack the Kingdom. With Sonia and Zelda's power assisting him, Rauru was able to defeat the swarm and temporarily stop Ganondorf. The Imprisoning War later began when Ganondorf killed Sonia and took her stone, transforming himself into the Demon King. Rauru sacrificed himself to stop Ganondorf, an act which killed Rauru and kept Ganondorf beneath Hyrule Castle for thousands of years. Mineru was injured during the fight, and died soon afterwards, leaving her spirit inside the Purah Pad. After this event there were no longer any living Zonai in Hyrule.
After the Upheaval, Link finds himself on the Great Sky Island. He interacts with the various constructs still there, receiving the Purah Pad from a Steward Construct, and defeating roaming Soldier Constructs. He soon meets the spirit of Rauru, who guides him to completing four Shrines across the Island, and opening the Temple of Time.
Midway through Link's adventure, he interacts with Mineru's spirit, who was still residing within the Purah Pad. After building a construct body for her, and retrieving her secret stone, she helps Link by giving him the construct for use to defeat enemies at any time. She further describes Zelda's actions in the past, and gives him knowledge of where the Master Sword may be.
Once Link has defeated the Demon Dragon and eradicated Ganondorf, Rauru and Sonia's spirit reappear, using their combined efforts to transform the Light Dragon into Zelda once more. Behind the Temple of Time, Link and the living Sages bid farewell to Mineru, who departs to the afterlife.