1. Different meanings: preface, also called introduction, is a short essay written in front of a book or an article, similar to preface or introduction, and the abstract refers to the main points of the excerpt.
2. Different emphases: The preface is the first part of the paper, which is used to introduce the background of the problem, other people's research achievements and shortcomings (brief literature review), thus leading to my own research motivation and the significance of this paper.
3. Different sources: The preface comes from Cao Jinghua's "Making Honey after Picking Flowers": "In short, these prefaces and postscript can be said to be a key for readers."
4. Different functions: Abstract can make readers know the main content of the paper, and whether readers will continue to read other parts of the paper after retrieving the title of the paper can be judged mainly by reading the abstract, which also provides convenience for scientific and technological information personnel and computer retrieval. The introduction mainly puts forward the problems studied in this paper and guides readers to read and understand the full text.
5. Different characteristics: the abstract is independent and self-evident, and has the same main information as the paper, that is, you can get the necessary information without reading the full text. Introduction is a part of the text of the paper and a prelude to the paper. It is not self-evident, so it is impossible to write independently.