A literature review provides an overview of previous research on a topic that critically evaluates, classifies, and compares what has already been published on a particular topic. It allows the author to synthesize and place into context the research and scholarly literature relevant to the topic. It helps map the different approaches to a given question and reveals patterns. It forms the foundation for the author’s subsequent research and justifies the significance of the new investigation.
A literature review can be a short introductory section of a research article or a report or policy paper that focuses on recent research. Or, in the case of dissertations, theses, and review articles, it can be an extensive review of all relevant research.