Open the books in ancient and modern times, at home and abroad, in order and out of order. Li Ying, a famous poet, has published more than 40 poems, almost all of which have no preface. In some books (especially ancient books), there are often many prefaces before the volume. It can be seen that whether a book needs a preface is a matter of different opinions. Personally, I think it is best for a book to have organized words. I have always regarded the preface of each book as a "channel", "bridge" and "medical introduction".
Ordered books can be self-ordered, tend to explain the purpose and process of writing books, and can also write other things that readers want to know. Most books are prefaced by others. No matter the preface or the preface of others, the preface usually precedes the text of the book and the postscript follows. But there are exceptions, such as Preface to Taishi Gong, which is put at the back of the book and becomes a special style. We often read another kind of preface in ancient Chinese, such as Liu Zongyuan's preface to Xue Cunyi, Han Yu's preface to Meng Dongye, and Li Bai's preface to the spring banquet in Taoliyuan. , belongs to the "preface", mostly in American, different from the preface.