A literature review summaries the knowledge of a particular area or field of study. A literature review may stand alone as an individual document in which the subject is analyzed for trends, controversial issues, and what still needs to be studied; these "review articles" are valuable time-savers for professionals and researchers who need a quick introduction or analysis in that subject area.
Examples of review articles:
Literature reviews are also part of dissertations/theses, research reports and scholarly journal articles; these types of documentation include a literature review in a chapter/section that discusses what has gone before and how that supports the issue under current study. Without a thorough literature review the academic may be repeating research that has already been discovered and the professional may be losing time and money to recreate from scratch what is already available.
Expamples of items that contain a literature review as a part of the document:
The research databases and searching techniques are the same for both types of literature reviews; however, how they are written and their purposes are different.