"Peer review" is the process through which experts in a field of study examine and assess the quality of articles before they are published. 

Sometimes the term "refereed" is used instead of "peer reviewed".

You can identify Peer reviewed journals in our database, Ulrich's:

Almost all library databases that have peer reviewed or scholarly articles have a box, or tab, or function that allows you limit searches or search results to peer reviewed/scholarly.

On Academic Search Premier it is a box that you can check to limit results to scholarly articles.  Easiest way to search for just what if you are looking for peer reviewed/scholarly articles.