Preface is the beginning of planning, which concisely states the background, basis, purpose, significance and guiding ideology of planning. The plan. Usually one or two natural paragraphs are enough.

Foreword, also known as preface, preface, narration, context, quotation and rumor, is written in front of a book or an article. The preface of the book, published before the text, mainly explains the basic content, compilation (translation) meaning, writing process of the book, academic value and translator's introduction. Written by translators, editors or others. The preface in an article is usually used to explain the main idea or purpose of the article. It can also be understood as the essence of what is written.