It is a brief statement of the content of the paper, without comments and annotations, and requires a brief description of the purpose, research methods and final conclusion of the research work, with the focus on the conclusion. This is an independent and complete paper. According to different contents, abstracts can be divided into three categories: reportable abstracts, indicative abstracts and reportable indicative abstracts.

1. The reportorial abstract is also often called informative abstract or informative abstract, which is characterized by comprehensively and briefly summarizing the purpose, methods, main data and conclusions of the paper. Or simply refine the paragraph sentences to reveal the whole picture of the paper concisely and logically. Usually, this abstract can partially replace reading the full text.

2. Indicative abstracts are also often called descriptive abstracts, descriptive abstracts or subject abstracts. Generally, only two or three sentences are used to summarize the theme of the paper, and arguments and conclusions are not involved. They are mainly used for abstracts, meeting reports, etc. This abstract can be used to help potential readers decide whether they need to read the full text.

3. The indicative summary of the report describes the part of the document with high information value in the form of report summary, and the rest is described in the form of indicative summary.