A review article is an article that summarizes the current state of understanding on a topic.[1] A review article surveys and summarizes previously published studies, rather than reporting new facts or analysis. Review articles are sometimes also called survey articles or, in news publishing, overview articles. Academic publications that specialize in review articles are known as review journals. Review articles in academic journals analyze or discuss research previously published by others, rather than reporting new experimental results.An expert's opinion is valuable, but an expert's assessment of the literature can be more valuable. When reading individual articles, readers could miss features that are apparent to an expert clinician-researcher. Readers benefit from the expert's explanation and assessment of the validity and applicability of individual studies.Review articles come in the form of literature reviews and, more specifically, systematic reviews; both are a form of secondary literature.[5] Literature reviews provide a summary of what the authors believe are the best and most relevant prior publications. Systematic reviews determine an objective list of criteria, and find all previously published original experimental papers that meet the criteria; they then compare the results presented in these papers.Some academic journals likewise specialize in review of a field; they are known as review journals.The concept of "review article" is separate from the concept of peer-reviewed literature. It is possible for a review article itself to be peer-reviewed or non-peer-reviewed.