A literature review is a "summary of what is currently known about some issue or field on the basis of research evidence, and/or what lines of arguments there are in relation to that issue or field" (Hammersley, 2004, p. 577).
As a researcher, you should be familiar with the signifigant literature related to your topic so that you can provide an overview of the work on your topic or field of study. The literature may come from journal articles, books, government documents, reports or other documents. A literature review usually contains a summary, a synthesis or an analysis of the central arguments in the existing literature.
For historians, a literature review is also known as a "historiographical essay."
Hammersley, M. (2004). Literature review. In M. S. Lewis-Beck, A. Bryman & T. F. Liao (Eds.), The SAGE Encyclopedia of Social Science Research Methods (pp. 557-558). Thousand Oaks, CA: SAGE Publications, Inc.
The purpose of a literature review is to: