1. They are written by academics and professors, aimed at fellow scholars in the field
But this does not mean that undergraduates or non-academics cannot use them, only that they will be professional in nature and in accordance with the professional standards of that discipline -- a good thing for you!
2. The language is scholarly and/or technical
3. The articles include extensive documentation and bibliographies
4. Published by scholarly or university presses
5. They often do not exist to make money. Their goal is not monetary, rather it is to contribute to that specific field.
Check out this handy chart for additional information regarding the differences between scholarly and popular publications.
Scholarly Journals vs. Popular Magazine Articles from the University of Texas at San Antonio
Peer-Reviewed materials are publications that have been reviewed by expert readers prior to their publication. Also called "Refereed" materials, these sources have been evaluated by experts in that particular discipline for accuracy, merit, methodology, and overall contribution to that specific discipline. These reviewers will alert the publisher of the material to any mistakes etc. that should be corrected prior to publication. This review process provides that only solid, well-done, and timely articles will be included in these publications. Generally, this is why your professor will encourage you to use these sources.
Note that "scholarly” and “peer-reviewed” are related but not the same: not all scholarly sources are necessarily peer-reviewed, but most peer-reviewed articles would be considered scholarly.
Confused? If so, ask your professor or your friendly reference librarian.
When an author submits an article for publication, that articles goes before a review board of experts in that field who scrutinize that article for accuracy, relevance, currency, and any errors. They then make recommendations for corrections prior to publication. Once these recommendations have been met by the author, the article is included in that journal.
In addition to articles, academic journals include other editorial content, such as book-reviews, editorials, and letters from academics. Although some of the editorial content can be useful, generally, when your professor says that you need a "peer-reviewed" source he/she means an article--not something from the editorial content.
Remember, not all journals are peer-reviewed. For tips on finding articles in peer-reviewed journals go to Finding Peer-Reviewed Articles in Library Databases.
These are peer-reviewed in that the author has created this source under the guidance of their mentor and committee who deem this work to be a contribution to the field.
Most conferences have a review committee that accepts the highest-quality presentations. After presentation, this review committee chooses exceptional papers to publish from the accepted presentations/papers.
Remember to check whether a conference has been peer-reviewed.
Popular Magazines and Periodicals:
Ex. Newsweek, Time, Cosmopolitan, Sports Illustrated
Ex. Advertising Age, Construction Today, Money Management, Publishers Weekly
From Cornell University Olin Library's "Research Minutes" series: