As an important part of books, it originally refers to classics in China. Books include books, picture albums, pictures and other publications. Books are works that record all kinds of knowledge on certain materials with symbols such as words and pictures, clearly express ideas and concepts, and make books. They are important tools for spreading all kinds of knowledge and ideas and accumulating human culture. With the development of human history, it is constantly changing and improving in writing methods, materials used, binding forms and forms.