It is usually presented as a distinct section of a graduate thesis or dissertation.
Students are often unsure of how to write a literature review.
The process of reviewing the literature requires different kinds of activities and ways of thinking.
Shields and Rangarajan (2013) and Granello (2001) link the activities of doing a literature review with Benjamin Bloom’s revised taxonomy of the cognitive domain (ways of thinking: remembering, understanding, applying, analyzing, evaluating, and creating).
Look at the following examples and see how the students summarise a number of studies and contrast differing findings.
Also notice the use of evaluative language to show the student's evaluation of the previous research."Several studies [5, 6, 7] have reported the benefits of using boron solid sources over other types of boron diffusion source. On the contrary, Warabisako et al  demonstrated that obtaining high efficiencies with boron solid source was no easy task.
In such a case, the review usually precedes the methodology and results sections of the work.
Producing a literature review may also be part of graduate and post-graduate student work, including in the preparation of a thesis, dissertation, or a journal article.
Literature reviews are also common in a research proposal or prospectus (the document that is approved before a student formally begins a dissertation or thesis).
A fourth type, the systematic review, is often classified separately, but is essentially a literature review focused on a research question, trying to identify, appraise, select and synthesize all high-quality research evidence and arguments relevant to that question.