Review articles are an attempt by one or more writers to sum up the current state of the research on a particular topic. Ideally, the writer searches for everything relevant to the topic, and then sorts it all out into a coherent view of the “state of the art” as it now stands. Review articles do not report the result of one particular study.
Research articles report the results of a particular study. They include a methods section that outlines how they did their study and a results section to report the outcomes.