Really, it is a good question. Let me answer this correctly. It is about culture. Basically human races came with different background. "Cultural background". The way of doing things in one culture may not be the way in other culture. What is good in one culture may be bad in other culture. Some time the activities are all the same in two different cultures, but two different meanings, two different interpretations.
When person from one cultural background, meet, interact with, understand and deal with person from other cultural background. That is cross-cultural management.
Some people are in favor of the world is converging; all things are going to be same. They are right. Some people are arguing still the world has divergence. They are also right. Don’t fight over this issue. We are smart people. Learn how to manage both the convergence and divergence. That is the key to success.
I will give you examples. In USA, it is performance that counts. Based on that you will be give higher assignments and promotions will be given. In Indian companies, performance is not the main criteria. It is "Organizational compatibility" that counts. That is the employee "fit" in to the organization that counts. India is a High context society. The "fit" in to the organization has to be interpreted in Indian way.
The business has different interpretation. In the USA, doing business means creating organizations wealth. In India doing business means "Individual wealth". On recruitment, In USA it is the process of selection, In India it is the process of rejection. And the difference goes on...
Certainly, the difference is innumerable. Increasing an individual's or an organization's cultural intelligence is not an easy task.