Language

I just wondering why some Chinese words can not be translated to English. 
I went to a Chinese restaurant for my lunch today. When I saw the word "dim sum," I was thinking whether it has a English vocabulary. Therefore, I searched the word "dim sum" on Google once I got back to home. The answer is NO. Then, I tried to find some more Chinese words that English cannot be explained and replaced. For example, the word snack does not equivalent the meaning in Chinese. In English, snack refers to potato chips, chocolates, candies…The Chinese food culture has many little dishes and "street food"(peddlers who offer fish balls, sausages, chinese dumplings) that is often translated in snack. Chinese people do not call them snack instead they are often be called as "xiǎochī".  It is interesting that culture in different countries have many vocabularies that are not able to describe in the other linguistics.