What does peer-review mean?
1. The review of commercial, professional, or academic efficiency, competence, etc., by others in the same occupation
-Oxford English Dictionary
Quick tip: use Ulrich's Periodicals Database to verify whether or not a journal or periodical source is peer-reviewed.
Articles provide information on very specific, narrow topics. The Library purchases article databases so you may access articles for your topic – for free. Researchers use them when they need: