Others include Zhuang, Miao, Urgur, Tibetan, Mongolian, Korean. Even among Han people, there are a lot of differences. Northern Hans are taller and characteristically more straight forward, eat more wheat products, Southerners are more slim and shorter, favor sweets, Hans in the mid provinces such as Sichuan and Hunan, because of the humidity, favor spicy food. Most of the ethnic people are more forthright and simpler than Hans in the east coast. Shanghainese are most famous for their shrewd calculations of every penny but no matter what their characters, if you treat them fair, they treat you fair.
China has one official language, that is Chinese.
Chinese in writing is same all over the country, but when spoken, it is a different story. Putonghua, or mandarin, is the universal language, understood by all educated Chinese. But there are thousands of different dialects in China. The differences in these dialects sometimes are more than two different languages. For How Are You, a Beijinger will say, Ni Hao, while a Guangzhouer will say Lei Ho.