The content of the introduction is generally to explain the background of the topic, including: the source of the topic and the research progress on this topic at home and abroad. Existing research achievements and existing problems. The significance of topic selection and the problems discussed. This paper is divided into several parts, from which aspects to discuss, as well as the guiding ideology, demonstration methods and so on. Can be written in the introduction according to the needs of the content.

Theory. Orthodoxy is often written in several parts, marked with "one", "two", "three" and "four" respectively, and some of them have subheadings or appear in the form of sub-arguments to highlight the viewpoints or main contents discussed. This part is the expression, analysis, induction and generalization of the research process, which embodies the analysis methods and ideas and fully demonstrates them. Orthodoxy should also embody clear guiding ideology.

Conclusion. Generally marked with "conclusion", "summary" and "conclusion". You can also write a conclusion or summary directly without labeling words such as "conclusion" after the theory. The conclusion is the induction, synthesis or generalization of the whole research work, and suggestions for further research can also be put forward. If you want to briefly discuss related issues after formalism, or think about more important issues, you can write a "conclusion". I found it online. I am a science and engineering student.