What are the subsets of classics and history?

The subset of classics and history is the four categories of ancient books in China. Some large-scale ancient books series often include four books and are named after them, such as Four Ku Quanshu, Four Series and Four Essentials. It can be seen that the four categories are of great significance to ancient books. The four-part classification of Classics, History, Zi and Ji is the product of China traditional culture, which is suitable for traditional cultural classics.