All scholarly sources are good; not all good sources are scholarly.
A New York Times article or government statistics are (probably) great, wonderful, reliable sources, full of credibility and accuracy and just the kinds of information you should trust.
They are not, however, "scholarly."
Scholarly is a very specific type of good, credible, reliable information source.
Scholarly sources are written by formally trained and educated experts in a field. They tend to provide an in-depth look at a very specific topic (as opposed to an overview or summary) and always have lots of sources cited to back them up. They are published by professional or academic organizations.
Some even go through a peer-review process before publication, through which other experts critically evaluate the content and evidence of an article.
Psychological Bulletin
Journal of Marriage and the Family
JAMA: The Journal of the American Medical Association
English Historical Review
After you know what an academic or scholarly article is, what then? Watch and see...
Here is an illustration of the differences between popular and scholarly articles, showing one of each type on the same topic (from Ohio University Libraries). The PDF contains two pages. Be sure to scroll to the next page to see the popular article.
Scholarly journal won't be making appearances at your local grocery checkout aisle. Journals like these, with circulations of two to four thousand, clearly aren't focused on wide appeal. They provide platforms for scholars to share groundbreaking research results that are often arcane and difficult to read for outsiders, and yet are often the only source for groundbreaking research in all fields, including humanities, social sciences, and hard sciences.
Here is what a typical scholarly article from a journal might look like.
A quick video on Research Articles and Peer Review: