A "general" article differs from a scholarly one in a number of ways. It could be written by a journalist, rather than a scholar, and published in a newspaper or magazine. Most journalism articles are not subjected to "peer review". (See the PowerPoint for a detailed explanation.)
Articles from trade and professional journals, general-circulation magazines, newspapers, or, today, from blogs or other web sources, are not considered scholarly sources.
This does not mean you can't use them in your essays; it merely means that you, as a researcher, have to distinguish between the scholarly and the non-scholarly article.