Peer review is one method of evaluating academic work. Specifcally, manuscripts are subjected to the scrutiny of peers, i. e., independant reviewers who are experts in the same fields as the authors, in order to assure the quality of publications. Peer review is used in most major scientific journals.
In Primo, there is a filter for peer-reviewed journals that allows you to limit results accordingly.
Hint: Get more relevant results for searches in the Articles+ scope by Changing the settings for ranking, so that articles in selected disciplines will be listed higher in result lists.