In general, the literature review should:

• provide a context for the research
• identify seminal works and scholars in the field
• acknowledge existing theories, points of view, hypotheses, etc. in the field of research
• justify the research
• clear up misconceptions about previous research
• ensure the research has not been done before (or if it is repeated, that it is marked as a "replication study")
• show where the research fits into the existing body of knowledge
• enable the researcher to learn from previous theory on the subject
• illustrate how the subject has been previously studied
• highlight flaws in previous research
• outline gaps in previous research
• show that the work is adding to the understanding and knowledge of the field
• help refine the topic, refocus the topic, or even contribute to the topic's evolution