By “key concepts in Chinese thought and culture” we mean concepts and keywords or phrases the Chinese people have created or come to use that are fundamentally pertinent to Chinese philosophy, humanistic spirit, way of thinking, and values.
The forefathers of the Han people living in the Central Plains referred to themselves by this term. Earlier on they called themselves Hua (华), Zhuhua (诸华), Xia (夏) or Zhuxia (诸夏). The term Huaxia (华夏) embodies the common identity of the way of life, language, and culture of the people living in the Central Plains, mainly the Han people, and the inheritance of such identity. The Huaxia people evolved into a fairly stable ethnic group in the Qin Dynasty, which established a unified country of many ethnic groups with Huaxia being the principal group. In the Han Dynasty, the term Han became an alternative name of Huaxia. Later, the term Huaxia was extended to refer to China or the Han people.
The Chinese character 夏 (xia) means big and great. Since the ancient Huaxia people practiced grand and elaborate rituals, they called themselves Xia (great). Their dresses were resplendent, so they were referred to as Hua (splendid). Therefore, both Hua and Xia refer to the Han people. (Kong Yingda: Correct Meaning of Zuo’s Commentary on The Spring and Autumn Annals)