Writing a literature review is a non-linear process. You may decide to revise your research question, find more resources and discard resources you've already found, change the way you want to structure your literature review, or how you want to address theories and ideas. Also, as you find resources on your topic, you will find that what you're writing is part of a larger conversation. There are already leading theories and a history on the topic you're pursuing and leaders who are already publishing their ideas. You'll become part of that conversation.
An overview of the subject, issue or theory under consideration, along with the objectives of the literature review
Division of works under review into categories (e.g. those in support of a particular position, those against, and those offering alternative theses entirely)
Explanation of how each work is similar to and how it varies from the others
Conclusions as to which pieces are best considered in their argument, and make the greatest contribution to the understanding and development of their area of research
The literature review does not present new primary scholarship. That comes in the section of your research that describes your experimentation (see the Research Process tab under Getting Started With Research).
When a literature review stands alone, it is reviewing what is known about the topic, analyzed for trends, controversial issues, and what still needs to be studied to better understand the topic at hand. A stand-alone literature review can be as short as a few pages or may be more extensive with long bibliographies for in-depth reviews.
Literature reviews can be used as part of dissertations, theses, research reports, and scholarly journal articles. They generally discuss what has been done before and how the research being introduced in this document fills a gap in the field's knowledge and why it is an important.