The following should roughly be the structure of a report. Note that these are just guidelines, not rules.
Title and abstract: These are the most important parts of a report. This is how you attract attention to your writing. The title should reflect what you have done and should bring out any eye-catching factor of your work.
Introduction: Most reports start with an introduction section. This section should answer the following questions. After title/abstract introduction and conclusions are the two mainly read parts of a report.
Background: This is expanded upon into a separate section if there is sufficient background which the general reader must understand before knowing the details of your work. It is usual to state that “the reader who knows this background can skip this section” while writing this section.Past/related work: It is common to have this as a separate section, explaining why what you have done is something novel. Here, you must try to think of dimensions of comparison of your work with other work.
Technical sections: The main body of the report may be divided into multiple sections as the case may be. It makes sense to mention the following main points:
Results: This is part of the set of technical sections, and is usually a separate section for experimental/design papers. You have to answer the following questions in this section:
Future work: This section in some cases is combined along with the “conclusions” section. Here you state aspects of the problem you have not considered and possibilities for further extensions.
Conclusions: Readers usually read the title, abstract, introduction, and conclusions. In that sense, this section is quite important. You have to crisply state the main take-away points from your work. How has the reader become smarter, or how has the world become a better place because of your work?