Scholarly articles are primarily intended for an academic audience and are typically published by an academic press. These articles report original research or provide in-depth analysis on a particular topic. Often, these publications are peer-reviewed, or screened by experts in the field.
The categories at the left are somewhat fluid. Popular articles are sometimes included in the same category as news and opinion. Both kinds are intended for a general audience and are meant to inform or entertain. They are typically written by professional staff writers or freelancers.
These links contain more information about how to tell the difference between different types of publications
Scholarly v. Popular Sources - University of Victory Libraries
Popular v. Scholarly Sources of Information - The University of British Columbia