What place did the ancient Central Plains refer to?

The Central Plains has the following meanings in China ancient sayings and Chinese historical materials and books:

One is the plain, vilen. "Poetry Xiaoya auspicious day": "Looking at the Central Plains, there is something to do"; "Zuo Zhuan Xigong Twenty-three Years": "Chu Jin ruled the soldiers, met the Central Plains, and ruled the three families."

Relative to the border areas, the corresponding areas are called Middle Earth and Zhongzhou.

In a narrow sense, it refers to Henan area. In the pre-Qin period, it was said that Luoyi (now Luoyang) and Tao Tao (now Dingtao County, Shandong Province) were the centers of the world. With the migration of the Chinese nation to the surrounding areas and the expansion of its activities, ancient Yuzhou was regarded as the center of the world. In the fourteenth year of Yongle in the Ming Dynasty: "Fu Weijing, south of the Central Plains."

Broadly speaking, it refers to a large area in the middle and lower reaches of the Yellow River, or refers to the Yellow River basin. Biography of Li Gang in Song Dynasty: "Since ancient times, the Lord of Zhongxing started in the northwest, so it is enough to have the southeast according to the Central Plains". The Central Plains refers to the middle and lower reaches of the Yellow River, and Zhuge Liang's "example": "When the prize rate is 3,000, the Central Plains is located in the north" refers to the Yellow River basin.

The ancients often used "China" and "Zhongzhou" as synonyms of Central Plains. It is generally believed that the ancient Central Plains refers to the middle and lower reaches of the Yellow River, with ancient Yuzhou as the center and Chinese tribes concentrated. With the great integration of the Chinese nation, Chinese culture or Zhou Wenhua has expanded and spread. Living in the middle and lower reaches of the Yellow River, Chinese people with advanced culture regard themselves as civilized and call themselves Huaxia, which is what distinguishes them from Siyi. With the spread of Chinese culture, some surrounding areas that were barbarians in Xia and Shang Dynasties were also included in the Central Plains Cultural Zone. In fact, apart from Henan Province, the Central Plains in two weeks mainly includes parts of Shaanxi, Shanxi, Hebei and Shandong provinces.