The next step researchers undertake is to conduct background research through a literature review, which is a review of any existing similar or related studies. A visit to the library and a thorough online search will uncover existing research about the topic of study. This step helps researchers gain a broad understanding of work previously conducted on the topic at hand and enables them to position their own research to build on prior knowledge. Researchers—including student researchers—are responsible for correctly citing existing sources they use in a study or that inform their work. While it is fine to borrow previously published material (as long as it enhances a unique viewpoint), it must be referenced properly and never plagiarized.
Taken from Introduction to Sociology 2e by Openstax is licensed under CC-BY 4.0
A literature review gives the reader background into the published literature of the topic and/or field of study the author is presenting.