The review papers (including meta-analysis) clarify the problems by sorting out, synthesizing and evaluating the published materials and investigating the current research progress. In a sense, summarizing the thesis is instructive, including the following contents: defining the problem; Summarize the previous research, so that readers can understand the current situation of the research; Find out all kinds of relationships, contradictions, gaps and inconsistencies in the literature; Suggest the next steps to solve the problem. Summarize that the organizational form of the paper is organized according to the logical relationship rather than the research process.

Review, also called literature review, is called review in English. It is a paper based on published literature.

Summary includes "synthesis" and "narration". The so-called synthesis means that the author must summarize and analyze a large number of existing materials to make them more refined, clear, hierarchical and logical. The so-called narrative is a comment, that is, a comprehensive, in-depth and systematic exposition of the topic written. Therefore, the abstract is a scientific and technological paper that is rigorous, systematic, critical and knowledgeable about the historical background, previous work, focus of debate, research status and development prospect of a certain topic and field. , writing the author's own point of view.