A review article is a journal article that summarizes the current state of understanding on a topic within a certain discipline. A review article is generally considered a secondary source since it may analyze and discuss the method and conclusions in previously published studies. It resembles a survey article or, in news publishing, overview article, which also surveys and summarizes previously published primary and secondary sources, instead of reporting new facts and results. Survey articles are however considered tertiary sources, since they do not provide additional analysis and synthesis of new conclusions. A review of such sources is often referred to as a tertiary review.

Academic publications that specialize in review articles are known as review journals. Review journals have their own requirements for the review articles they accept, so review articles may vary slightly depending on the journal they are being submitted to.

Review articles teach about:

A meta-study summarizes a large number of already published experimental or epidemiological studies and provides statistical analysis of their result.

Review articles have increased in impact and relevance alongside the increase in the amount of research that needs to be synthesised. They are a concise way of collating information for practitioners or academics that are not able to read the plethora of original research that is being published.

There are various categories of review articles, including narrative reviews, systematic reviews, and meta-analysis. Review articles do not introduce new results, but rather state existing results, drawing conclusions on the results presented. Review articles can be categorised by using the same domain, underlying theory, or research method. Sometimes these categories overlap.

Narrative reviews describe the published information on a theme or topic, but often does not include the methodological process involved in researching the topic. This can lead to narrative review articles being biased, missing important theoretical details pertaining to the original research, and innovative suggestions to further develop the field through further studies.

A systematic review is more detailed and structured than a narrative review. It details the aims, hypothesis, and research method clearly so as to remain transparent and neutral. This review format adheres to explicit criteria when selecting what research is included in the review. Common methods used to analyse selected research articles include text mining, citation, co-citation analysis, and topic modelling. These types of reviews also include a discussion on the theoretical implications of such research. Systematic reviews are more highly regarded and selected than narrative reviews due to their specificity and neutrality. In the field of clinical research, the Cochrane organisation publishes systematic reviews (called Cochrane Reviews) on healthcare topics in the Cochrane Database of Systematic Reviews.