An article is considered scholarly or peer-reviewed if it appears in a journal that requires a pre-publication review of its articles. In a NUTSHELL - It doesn't get published until the EXPERTS in the field say its okay.

Ulrich’s Web – The most comprehensive guide to journals. International in scope, this is the ONLY source that will verify whether or not a journal is peer-reviewed. This will give you all of the publishing information regarding a journal.