North is generally colder in climate to the more tropical and warmer South, Northern Chinese traditionally eat grains and wheat-based foods like baozi and jiaozi (dumplings) while Southern Chinese will eat rice and rice-flour based foods like rice noodles. Northern China was occasionally under the influence of nomadic powers which shaped its culture. Southern culture is shaped by the gradual immigration of Han Chinese peoples from the North and assimilation of the native peoples into Han Chinese. Roughly before 1000 AD, Northern China was more economically powerful and the South was generally a hinterland while roughly after 1000 AD Southern China was more economically powerful (for example, see Guangdong/Canton region). Non-Han tribal minorities in the North tend to be descended off nomadic horse tribes while in the South they are usually descended off river and mountain-based tribes.

As of Modern China, the North tends to be politically powerful as it is dominated by Beijing while the South tends to be economically powerful, dominated by Shanghai, Guangdong/Canton, Shenzhen, etc.

For more info, click here: https://en.wikipedia.org/wiki/Northern_and_southern_China

To some degree, similar to the North-South Indian cultural divide if you want to look that up too.

To add on to the informative sibling comment, historically South China communities have been more isolated from each other due to its rugged terrain, whereas North China has been dominated by its plains, especially the central plain. Hence the phenomenon that in the North, historically, Mandarin dominated as the lingua franca, whereas the south was host to a staggering variety of Chinese languages.

Very different foods. The north is a lot more spicy stuff. The south is more about sauces and freshness.