Xiaomi phones are products of Xiaomi Company, including Redmi phones, Black Shark gaming phones, and other products.
Xiaomi is an internet company in China founded by Lei Jun. They do not have their own factory and integrate resources from other factories to create their own brand phones.
The reason why Xiaomi phones can succeed is because their prices are cheap enough, and they have started to accumulate a large number of users, gradually improving their phones.