Peer Review Definition
The peer review process involves a committee of scholars reviewing an article or book for publication before the item gets published. This process adds an extra layer of quality to the publication. Often your professor will require a certain number of peer reviewed articles or books. You can limit your search in advance, using the advance search feature, to yield only peer reviewed sources or you can filter your search after the fact to yield only peer reviewed sources. In addition, often the journal's home page will mention if the journal has peer review status, typically in the "about" section of the homepage.