Is Zhouyi used for fortune telling or for what?

It was used for divination in ancient times. Later, it gradually became a science for people to study, which contains very strong philosophical knowledge and is an important classic full of the wisdom of ancient people in China. The divination of Zhouyi (that is, fortune telling bar) is very complicated, and it can't be explained clearly in a few words. So many people study it for different reasons. Some people may really want to know the destiny after reading the Book of Changes, and some people may understand the spirit of the characters for their own use. Since you are interested in this, I recommend you to read the Book of Changes by Nan, a master of Chinese studies, which can be used as a good way for you to understand the Book of Changes. However, it is difficult to really understand the Book of Changes, and it is better to concentrate on practicing after understanding it.

Well, on the surface, it is a calculation, but in fact it contains more than that.