Question

What is the difference between "China A" and "China B"?

Answer 1

China A is understood to be the richer part of China: typically it's the part of China that is the more developed and richer, and typically it's also the urban population. China B is the poorer, typically urban part of China.

The correct answer is:

"China A" is urban, more affluent and rapidly developing; "China B" is rural, poor and not developing.

Similar distinction is done in other countries too.