Usually only available by subscription (not found in bookstores or newsstands). Academic libraries subscribe to thousands of journals. Check the library catalogue.
In peer-reviewed journals (also called refereed), the articles are reviewed by other experts in the same field of study before they are accepted for publication. Reviewers often suggest revisions before publication... or may suggest that the article be rejected. Usually the editor(s) of the journal make the final decision.
In the article, the author's credentials are listed and are relevant to the subject of the article.
A reference (or citation) list is included at the end of the article, allowing readers to trace the information the author has cited.
Peer reviewed journals are often published by a scholarly society, university press, or commercial publisher specializing in academic publications (e.g. Wiley or Elsevier).
The intended audience is professionals, researchers, or students in the discipline; and the language is often technical, requiring prior knowledge of the field.
Popular magazine articles:
Popular magazines and newspapers are found on newsstands.
The author may be a staff writer or journalist, who may not have an academic background in the subject matter.
References or citations are rarely included at the end of an article or within the text of an article.
This table produced by UBC Library provides a useful comparison of the differences between scholarly and popular articles. Popular articles are usually considered secondary literature (one exception might be in the discipline of History).