Introduction, as the first chapter, is the beginning of the main body of graduation thesis. The introduction should include: the background and purpose of graduation thesis; Research status at home and abroad and existing research results in related fields; Research methods, research results and conclusions.

Preface is the beginning of an argumentative paper, that is, to ask questions and clarify the central argument, so that readers can have a general understanding of the content of the article and attract attention.

Common preface writing methods include: directly stating one's own views and opinions and putting forward central arguments. Explain the background, the purpose and reason of writing. Tips, briefly introduce the full text.