xiongmaoboy: Hello.
Sixty Flower Jiazi is divided into thirty Nayin and Five Elements, such as gold in the sea, Tianhe water, etc. It is the category of five tones and six rhythms, which is called "Nayin and Five Elements".
It is divided into five lines according to the eight characters, which are the positive five lines. These are the basic five elements of fortune-telling. Sometimes the positive five elements are not enough, so I refer to the five elements of Nayin. Then there is the year pillar of a person's destiny, which is often labeled "Nayin Five Elements". It is just a symbol and does not play much role in destiny.
If you want to delve deeper, it is recommended to study the book "Heluo Jingyun". It will be helpful to you.