There are 1,300 million of them and they're all called Chinese. The European Union has a third that number. They are all called Europeans but no one expects them to be the same. We recognise that Bulgarians are different from Spanish and Italians from Danes. The same goes for China. Thirty percent of the population is officially recognised as belonging to minority groups. In Britain they would be called nations (English, Scots, Welsh). The rest of the Chinese population is classed as Han.
Don't think of the Han as being all the same. For starters, they don't all speak the same. The Shanghai "dialect" is as different from the official Beijing "dialect" (Mandarin) as English is from broad Irish or Scots. Cantonese, sounds so different that even foreigners can tell it apart from Mandarin.
The big unifying factor is writing. Most Chinese characters do not spell out sounds. They convey meaning (like our traffic signs). As a consequence, people with totally different languages can communicate through writing. You will see Chinese handing one another writing pads. They're not asking for an address. They want the other person to write down what they are saying so they can understand.
The Chinese people not only speak different languages, they have different cultures and temperaments. Up north, they are more reserved (like Japanese and northern Europeans). People in Beijing tend to be formal but the same cannot be said for Shanghai. Down south, in the Cantonese speaking regions, they are positively effusive.
In the mountainous borderlands to the north of Vietnam, Laos and Myanmar (Burma), ethnic groups differ from one valley to the next and spill over into neighbouring countries. There is a long history of ethnic tension and hostility to the central government.
In the vast, sparsely populated western regions, the people are even more varied. Many Tibetans do not regard themselves as Chinese and the same can be said for many Muslims in Sinkiang.
Interestingly, many of the “minority groups” were not subjected to the full-rigors of the “one-child” policy and were allowed to have more than one child.
My photos of people show the differences between the different ethnic groups. And they have been picked to do just that. Some show people who are still living in the way of their ancestors. It would be wrong to think that all members of their group live like that. I could have shown you shots of Tibetan girls in swimming costumes and Tungusic kids with computers. I have pictures of Yao businessmen in business suits and Turkic farms with TV-dishes but I chose not to show them.
Photos (top to bottom): Shanghai, Tajik, Miao, Yao, Tibetan, Mongolian, Turkic. Tungusic.