Not all items that appear in peer reviewed journals are actually peer reviewed. Articles that require a certain level of scholarly effort such as research studies, experiments and literature reviews are peer reviewed. Items appearing in peer reviewed journals that are not peer reviewed are;
Keep that in mind when you limit your search to peer review. The results list may contain some of the above items that are not peer reviewed. Make sure you check what type of item you are looking at before you assume it is peer reviewed simply because it appears in a peer reviewed journal.
Most library databases contain a variety of materials including magazines, scholarly journals, newspapers, etc. You can limit your search to include only those articles from scholarly or peer-reviewed journals. Below is an example from the Academic Search Complete database: