Most scientific articles start with an abstract or a summary briefly outlining the content of the article. Also, larger university assignments often require an abstract. Read more in the academic regulations for your programme.
The recommendations for where the abstract should go vary from programme to programme. The abstract can be placed at the beginning of the assignment, or at the end. Ask your teacher.
An abstract gives your reader a quick overview of the topic, even if he or she is not an expert. Also, it enables the reader to decide whether the assignment is relevant for them.
Different referencing systems provide specific guidance on how to write an abstract. See, for example: the APA style or the MLA style.
The information about formalities is written in collaboration between Center for Educational Development (CED) and AU Library and is general guidelines for formal requirements. They do not replace the provisions in your academic regulations, your lecturers' guidance or information on your course's website. If in doubt ask your supervisor.