. "Preface" is referred to as "preface", also called preface. It is a practical style and is the same as "postscript". Listed at the beginning of the volume is called a preface, and appended to the end of the volume is called a "postscript". Its function is to recommend and introduce someone's work or a certain material, explain the writing process, writing purpose, main content or explain some things related to the book to help readers read or understand better. Some prefaces are written by oneself, which are called "self-prefaces"; others are written by others, which are called "other prefaces". In addition to introducing the work, other prefaces often include some evaluation content.
Whether it is ancient times or today, there is a kind of article called "preface"