Peer-reviewed articles can be found in scholarly or academic journals, and before they are published, they go through a rigorous review process by a group of experts. In this peer-review process, an article written by an expert in a particular field of study is reviewed by a panel of individuals who are also experts in that academic subject; they are the scholarly "peers" of the person who wrote the article.
Peer-reviewed articles include research studies and critical overviews of industry topics. The review panel members use a strict set of standards to determine the quality of the article and ultimately decide if the article will be published in that journal. This review adds an element of authority and validity to the article due to the confirmation from other experts within that field.
Peer-reviewed articles are considered more scholarly in nature, which is why they are often required for research assignments. In fact, they are often referred to as “scholarly” articles in your assignments.
See this table for a comparison of peer-reviewed journals to other types of resources.