What is a peer-reviewed journal, also known as a refereed journal?

A scholarly periodical which requires that each article submitted for publication be judged by an independent panel of experts (scholarly or scientific peers). Articles not approved by a majority of these peers are not accepted for publication by the journal.

Peer-reviewed journals can be identified by their editorial statements or instructions to authors (usually in first few pages of the journal or at the end), and also by consulting Ulrich's International Periodicals Directory.
 

Other common characteristics of scholarly, peer-reviewed, or refereed journals:

• Formal in format
• Sources are cited with footnotes or a bibliography at the end of the article
• Authors are scholars and researchers in the field and are identified as such
• Purpose of the article is to publish the results of research
• Publisher may be a professional organization, research institution; usually not-for-profit
• Very little advertising
• Graphics are usually statistical illustrations, in black-and-white