What Are Scholarly or Peer-reviewed Articles?
Definitions:
The following terms are sometimes used interchangeably to describe a journal or journal article: "scholarly," "academic," "peer-reviewed," "refereed," "empirical study," or "research." They're related but not necessarily the same. 
Scholarly or academic journals: usually refer to the journals in which the scholarship or research of an academic discipline is published. These journals include research articles, book reviews, editorials, letters to the editor, etc. Scholarly journals are usually but not always peer-reviewed.
Peer-reviewed or refereed journals: refer to journals that submit contributed articles to a panel of experts in the discipline for review before publication. Students are often advised to seek out peer-reviewed articles, as the peer-review process provides a greater assurance that the research presented is sound.
Research or empirical research: Research articles describe and document research and usually comprise an abstract, introduction, methodology, results, discussion, list of references, and appendices. Empirical studies are based on data derived from observation or experimentation.
Professional or trade journals: journals written for a particular profession or discipline but not peer-reviewed. It may or may not be considered scholarly.
How to Identify a Scholarly Article
Scholarly, peer-reviewed articles are resources that have been written by experts in the field and then reviewed by other experts in that field to ensure they meet academic standards.
They typically follow a similar structure and will have characteristics that you can learn to look for when you are researching. These include things like:
- the abstract which summarizes the contents of the article and why it is important,
- the author and their affiliations which help establish their credibility to write on the subject,
- and the references to citations that were consulted to give attribution where it is due and to connect researchers to the original source of information for additional context.
The resource below from North Carolina State University is an interactive tool to help you learn these and other clues for identifying a scholarly article.