A literature review is an thorough and up-to-date overview of existing research within a topic or field. Your literature will come from quantitative research, however, other literature reviews can come from other scholarly sources.
"It's a review because it usually contains a summary, synthesis, or analysis of the central arguments in the existing literature on the topic. A literature review does not present an original argument, but instead presents the arguments of others. The sources are the main focus in a literature review and the author summarizes the arguments or ideas of others. You should include only the most relevant sources on a topic. The literature review may also include gaps in the literature, identifying areas where further research needs to be completed." http://monmouth.v1.libguides.com/content.php?pid=162720
A literature review can have several purposes. It can: