Literature review and introduction

A literature review in an introduction provides an overview of past and current work in your research topic. It is usually summarized in the introduction of a thesis, and sometimes appears as a separate section. It outlines the main research questions faced in a given domain of research, and provides motivations and justifications for pursuing your research into the topic. As many students on an undergraduate level will not pursue a career in research, it's particularly important for an undergraduate thesis to understand the societal relevance of a topic and to anticipate applications of the research to "real-life" situations. Therefore, the literature review is often accompanied  by a description of the societal relevance of the research.

Literature reviews can be found in the introduction  practically in any refereed journal article. Almost every sentence in the introduction of most papers contains large numbers of citations, as the introduction summarizes the most  important facts, theories and science on which your paper rests on. You can (almost) never have to many references in an introductory literature review.