A scholarly publication is one in which the content is written by experts in a particular field of study - generally for the purpose of sharing original research or analyzing others' findings. Scholarly work will thoroughly cite all source materials used and is usually subject to "peer review" prior to publication. This means that independent experts in the field review, or "referee" the publication to check the accuracy and validity of its claims. The primary audience for this sort of work is fellow experts and students studying the field. As a result the content is typically much more sophisticated and advanced than articles found in general magazines, or professional/trade journals.
In brief, scholarly work is:
To see the typical components of a scholarly journal article check out the Anatomy of a Scholarly Article from North Carolina State University Libraries (resource may not be accessible).
While many of your research projects will require you to read articles published in scholarly journals, books or other peer reviewed source of information, there is also a wealth of information to be found in more popular publications. These aim to inform a wide array of readers about issues of interest and are much more informal in tone and scope. Examples include general news, business and entertainment publications such as Time Magazine, Business Weekly, Vanity Fair.
These are more specialized in nature than popular publications, but are not intended to be scholarly. These types of publications are aimed at experts in the field and/or keen amateurs, but the content focuses on news, trends in the field, promotional material etc. Research findings are not typically disseminated here - though they may report that a scholarly publication is forthcoming. These types of publications typically will contain more advertising than a scholarly journal - though it's usually targeted to the field in some way. Examples: Publishers Weekly; Variety; Education Digest
A formal structure in an article or book chapter often include headings such as "literature review," "results," "discussion," "conclusion." Full-length scholarly books (often called monographs) often contain similar sections.
(These questions adapted from the University of Michigan's "Is it Scholarly?" tool.)