Despite some variation in the structure of academic assignments, it makes sense to talk about a standard structure with specific fixed elements:
The page about the Structure of the assignment elaborates on the content of different parts of the assignment and the function they serve. In some academic traditions, it is common to have other sections as well, e.g. a literature review/state of the art, philosophy of science, or to give the reader insight into the academic tradition or field of research in some other way. Always ask your supervisor and check your academic regulations to find out about the formal requirements for such sections, as these vary greatly across programmes and courses.
Note! Some of the points may be irrelevant for your assignment or they may be called something else. The sections do not necessarily have to appear in the order described above. For example, assignments within the natural sciences will often follow the IMRAD structure.