A peer-reviewed article is an article that has been subjected to the analysis and scrutiny of qualified professionals before publication. Because of this review process, these articles are often preferred as references in academic research papers.
Peer-reviewed articles are always scholarly, but not all scholarly articles are peer-reviewed. Watch out for opinion pieces. Some scholarly journals include editorials or other opinion-based content, such as Letters to the Editor. You can often identify these works by their use of first person (I, my, etc.). Even if these are marked as 'peer-reviewed', they really aren't, so don't rely on them for your paper.
Where do I start looking?
Your college’s library databases are the best place to start when finding peer-reviewed articles. Databases and library searches should give you the option to limit your search to peer-reviewed and scholarly articles.
Look for check boxes with this option within each database (you may need to go into an advanced search menu). Learn more about peer-reviewed articles along with other types of resources.
Still not sure if your article is peer-reviewed? Check the journal/publisher website. Often they will tell you if the journal is scholarly or peer-reviewed.