Need to introduce. Abstract and introduction are two different parts of the paper, and they have different functions and purposes in the paper. It is a brief overview of the whole paper, and the introduction is a detailed introduction to the background, purpose and importance of the paper. Therefore, in a paper, abstract and introduction are essential. Abstract is the beginning of the paper, usually before the introduction. The main purpose of this paper is to provide readers with a quick overview of the contents of the paper, including the main research problems, research methods, main achievements and conclusions. The length of the abstract is usually between 100 and 300 words, which concisely expresses the core content of the paper. The writing should follow a certain structure, including background introduction, research purpose, research methods, main results and conclusions.