A peer-reviewed article is one that has gone through a standard review process 
by other scholars in a particular field to ensure the reliability of the material being presented. Articles in popular magazines have not undergone this process. Peer-reviewed articles can be found in journals published by academic institutions or professional organizations. They generally feature an abstract at the beginning and a large number of bibliographic references at the end.
You may find peer-reviewed journal articles in many of our Library databases. Try to find a relevant database in your subject. Some databases contain only peer-reviewed journal articles. Others contain both peer-reviewed and non-peer-reviewed articles. If a database contains both, there will be a box to check off on the search page that will allow you to limit to peer-reviewed articles only. (See example).