Peer-reviewed articles are publications reviewed by "experts in the field" prior to publication. After reading and evaluating the material, the reviewer informs the publisher if the document should be published or if any changes should be made prior to publication. Peer-reviewed materials are also referred to as Refereed. Peer-reviewed sources are significant to the research and the literature of most academic fields because they assure readers that the information conveyed is reliable and timely.
The video below will explain more about the peer-review process.
Many library databases, including Academic Search Complete and Academic OneFile, allow you to limit your search to only peer-reviewed journals. On the Advanced search screen of the database, look for a checkbox that says "Peer Reviewed."
The video below will show you additional ways to make sure a journal is peer-reviewed.