"Ancient" is relative to "present", and books printed without modern printing technology can be called ancient books.
Books began to appear when people began to consciously engrave on specific forms of materials to record knowledge and spread ideas. In the history of compiling ancient books in China, it is proposed that books must have the following six components:
1. Knowledge information;
2. The way of writing;
3. Text;
4. Material carrier;
5. Text production technology;
6. Binding form.
The traditional classification of ancient books in China adopts four parts: classics, history, sub-books and collections, and the four parts are subdivided into 44 categories.