Peer reviewed means each article has been subjected to a peer-review process in which a panel of experts in the field evaluates the academic rigor of the article's content. Basically, they ask themselves, Is this article scholarly enough to appear in this journal? Does it meet the academic standards of the field? To answer those questions, these experts scrutinize the article as impartially as possible. Those that are accepted are often sent back to the author for revision before they're published. Peer reviewed and refereed mean the same thing.