To determine if your source has been peer-reviewed, you can research the journal in which the article was published. Try visiting the journal's website and looking for information about its submission and review guidelines, or search for the journal's title in UlrichsWeb's global serial publications directory for more information on this subject. Academic articles are those that are reviewed by several experts in their related fields and then published in academic journals. The main purpose of academic journals is to represent and disseminate research and academic debates between academics (professors, researchers, students) within and between different disciplines academics.
When a source has been peer reviewed, it has undergone review and scrutiny by a review board made up of colleagues from the author's field. They evaluate this source as part of the body of research on a particular discipline and make recommendations regarding its publication in a journal, reviews prior to publication or, in some cases, reject its publication.