Every culture has set rules about how people should act. Patterns of good behavior, or manners, show respect and care for others. Yet the details of how to express respect vary.
Greeting people cheerfully is almost always considered polite. But it's more important in some cultures than others. For example, when you enter a store in France, you should always greet the person working there. Other cultures also value greeting people. But of course the greetings vary as people speak different languages.
When I was growing up in the United States, I once participated in a performance at my church. Afterward, someone gave me a compliment, but I felt like I had done a bad job. So I tried to refuse the compliment, saying, "No, I didn't do that well." My mother got my attention and told me that was very rude. Later I learned that refusing a compliment is accepted and even approved of in China.
Some of the biggest cultural differences have to do with table manners. In North America, it's polite to eat as quietly as possible. That means chewing with your mouth closed and not slurping(吃东西时发出的声音)your soup. The same goes for burping(打嗝). But in parts of Asia slurping shows that you are enjoying your meal. And burping is a sign of being full and content.
There are also differences in how people eat across cultures. For example, in North America and Europe people use forks to bring food to their mouths. But in Thailand, a fork is only used to push food onto a spoon. In India and the Middle East, people eat with their hands. But eating with the left hand is forbidden. This is because the left hand is considered unclean.
Yet there are also similar points across cultures. Saying "please" and "thank you", for example, is almost always polite. If you show appreciation and try to follow local customs, people will generally respond well. Showing kindness can bring people together, no matter what culture they come from.