A systematic review identifies, appraises and synthesises research findings using rigorous methods. The Cochrane Collaboration provides systematic reviews of healthcare interventions. They can be found in the Cochrane Database of Systematic Reviews which is part of the Cochrane Library. The Cochrane website provides the following definition of a systematic review:
A systematic review attempts to identify, appraise and synthesize all the empirical evidence that meets pre-specified eligibility criteria to answer a given research question. Researchers conducting systematic reviews use explicit methods aimed at minimizing bias, in order to produce more reliable findings that can be used to inform decision making. (Cochrane Library, 2017)
Systematic reviews are used in healthcare where the evidence has to be assessed in a systematic way, but the technique can be applied to other fields to assess the quality of research. The Campbell Collaboration produces and uses systematic reviews in the fields of crime and justice, education, international welfare and social welfare.
Both involve assessing the existing literature in a particular area. A systematic review is more rigorous and will look at all of the research available on a topic. Systematic reviews adopt a scientific approach and have specific inclusion and exclusion criteria. As well as presenting the results, systematic reviews also outline the search strategy, the inclusion criteria and synthesize the data.
If you are an undergraduate it is unlikely that you will have to find all of the information on your topic. You would be carrying out a review of the literature in a systemic manner.
Even if you do not have to conduct an actual systematic review, following the steps for such a review can help with planning and conducting your literature review.