"A literature review is an account of what has been published on a topic by accredited scholars and researchers. [...] In writing the literature review, your purpose is to convey to your reader what knowledge and ideas have been established on a topic, and what their strengths and weaknesses are. As a piece of writing, the literature review must be defined by a guiding concept (e.g., your research objective, the problem or issue you are discussing, or your argumentative thesis). It is not just a descriptive list of the material available, or a set of summaries."

From Yale University Library "The Literature Review: A Few Tips on Writing It," http://www.writing.utoronto.ca/advice/specific-types-of-writing/literature-review)