Scholarly materials are written by and for faculty, researchers or scholars using scholarly or technical language, include full citations for sources. Scholarly items are often refereed or peer reviewed. Book reviews and editorials are not considered scholarly articles, even when found in scholarly journals.
Popular materials are often written by journalists or professional writers for a general audience using language easily understood by general readers. Popular items rarely give full citations for sources, are written for the general public, and tend to be shorter than scholarly materials.