What is the meaning of "barbarians" in China's historical materials?

Barbarian warfare refers to uncivilized and uncivilized people. To put it bluntly, civilization and barbarism were very, very different at that time, just like showing the United States today the feeling of Africa now.

At that time, people also had their own ethical concepts, but this ethical concept was suitable for China and not for Siyi, because Siyi was "afraid of power and heartless", so etiquette education was not needed. Confucius said that "education without class" refers to the Chinese people, which has nothing to do with the four barbarians, because Confucius also said that "future generations do not seek summer, barbarians do not mess with China", and Confucius (in fact, everyone's concept at that time was in this regard.