A literature review is a summary of the published work in a field of study.
Divide the available resources that pertain to your research into categories reflecting their roles in addressing your research question.
Possible ways to categorize resources include organization by: Regardless of the division, each category should be accompanied by thorough discussions and explanations of strengths and weaknesses, value to the overall survey, and comparisons with similar sources.
A literature review creates a "landscape" for the reader, giving her or him a full understanding of the developments in the field.
This landscape informs the reader that the author has indeed assimilated all (or the vast majority of) previous, significant works in the field into her or his research.
Undergraduate students may find the page useful, but there is also a Write a Literature Review: for Undergraduates. A literature review is the basis of a graduate essay, Dissertation, Masters or Ph D thesis.
The purpose of a literature review is to find out what is already known about your topic.
Use citation searching to track how scholars interact with, and build upon, previous research: Key to your literature review is a critical analysis of the literature collected around your topic.
The analysis will explore relationships, major themes, and any critical gaps in the research expressed in the work.
The methodology used to collect research has to be consistent in order to reduce misinterpretation and misrepresentation of the data.
See Systematic Reviews: What is a systematic review?