Peer-reviewed articles (sometimes called refereed articles, or scholarly articles) are written by experts for other experts. They are published in peer-reviewed journals, which are often only available if you are affiliated with a library or school.
Peer-reviewed articles:
- are written by experts in a field
- go through a formal review process before they are published
- appear in peer-reviewed journals
- can take several forms -- some peer-reviewed articles share the results of independent research, some summarize research in an area, etc.