A literature review is a survey of the scholarly literature published on a given issue, research topic, or theory, and provides a description, summary, and critical evaluation of each work. Rather than providing a new research insight, a literature review lays the groundwork for an in-depth research project analyzing previous research.
Through a literature review, you are building a case to support your thesis.
Graphic from The Literature Review by Machi and McEvoy- originally uploaded by IUPUI University Library.
Okay, but what is "literature"? Published scholarly research (the "literature") may include journal articles, books, dissertations and theses, or conference proceedings.