Imagine you're playing with a toy city, with one street running from the top of the city to the bottom, and another street running from the left side of the city to the right side. Let's pretend that the city is divided into two parts, with the top half being the North and the bottom half being the South.
Now, let's say that the North has lots of resources, like money, technology, and skilled workers, while the South doesn't have as many resources. Because the North has all these resources, it can invest in things like factories and businesses, which create jobs and help the economy grow even more. This means that people from the South might move to the North for work, since there aren't as many job opportunities in the South.
Over time, this pattern of the North having more resources and more economic growth while the South has fewer resources and fewer job opportunities is called the north-south model. It's important to try and balance out this economic inequality so that both the North and the South can have strong economies and plenty of job opportunities for everyone.