What is a literature review?
"All reviews involve analyzing and synthesizing multiple studies for the purpose of demonstrating their collective relevance for solving some problem, for understanding some issue, for explaining some relationship, and so on. Reviewing is an interpretive undertaking insofar as it is an effort to make sense of these studies and to establish their meaning. A widely held view is that reviews are a means of collecting and organizing the results of previous studies so as to produce a composite of what we have already learned about a particular topic. This approach assumes that knowledge accumulates within a field, and hence understanding of some phenomenon can be built up piece by piece, brick by brick, eventually yielding something like a more complete, thorough, and, hence, trustworthy understanding, which, in turn, can be more confidently applied to solving a problem of a particular kind."
Schwandt, T. A. (2007). Review of literature, In The SAGE dictionary of qualitative inquiry Thousand Oaks, CA: SAGE Publications Ltd doi: 10.4135/9781412986281