"How Library Stuff Works: How to Evaluate Resources (the CRAAP Test." YouTube, uploaded by McMaster Libraries, 23 January 2015, https://www.youtube.com/watch?v=_M1-aMCJHFg.
A peer reviewed source is on that has been accepted by scholars and academic experts in a particular field. It means that groups of experts on a topic in a specific field have read the work and verified that it is good research that meets established and acceptable standards of scholarship for a particular discipline.
When an article is published in a peer reviewed journal or in a book by a reputable publisher you can feel confident that
Adapted from University of Illinois libguide "Peer Review An Introduction"