I often hear the words first-tier cities and World War II cities. I don't quite understand how these are divided.

A first-tier city refers to a metropolis that plays an important role in its own economy and politics. First-tier cities are generally ahead of other cities in terms of city size, infrastructure, fiscal revenue, consumption and attractiveness to talents. In business activities, enterprises will also refer to cities with important market position as first-tier cities. There is no fixed standard for the division of first-tier cities. It can be divided by administrative level, city size, population, economic development level and GDP. At present, the first-tier cities recognized in China are Beijing, Shanghai, Guangzhou and Shenzhen. The GDP of these four cities ranks among the top four in Chinese mainland, and they are also the most attractive cities for employment. At the same time, the concept of so-called first-tier, second-tier and third-tier cities, which is most frequently mentioned in China, originated from the real estate market. Conventional or main indicators include economic status, city size (population, area, etc. ), city level, influence, radiation, popularity, etc. Most first-and second-tier cities in China are municipalities directly under the central government and sub-provincial cities. At present, there are fifteen sub-provincial cities: Wuhan, Chengdu, Xi 'an, Harbin, Changchun, Shenyang, Dalian, Jinan, Qingdao, Nanjing, Hangzhou, Ningbo, Xiamen, Guangzhou and Shenzhen. Chongqing used to be a city under separate state planning, and 1997 became the fourth municipality directly under the central government of China. Dalian, Qingdao, Ningbo, Xiamen and Shenzhen are cities under separate state planning.

Remember to adopt