There are several factors to consider when evaluating journal articles.
"Peer reviewed" (or "refereed") means that an article is reviewed by experts in that field before the article gets published. Some databases allow you to limit your search to Peer Reviewed or Refereed articles. Often you can click on the journal title in a database and get information about that journal, including if it is peer-reviewed.
You can also check to see if a journal is peer-reviewed using Ulrich’s, a directory of all journals, magazines, news, and any other periodically-released resource. Type the journal title in the search box (leave off A, The, An, etc. at the start of the title) and either hit "Enter" or click on the search button (green magnifying glass).
Find your title in the search results and click on it to see the record. Look for “Refereed” and “Yes.” If you do not see “Refereed” in the Basic Description column, it is not. Refereed is the same as peer-reviewed.
A primary research article reports on the original research and findings of the authors. Primary research articles usually have the following (or similar) sections:
A secondary research article reviews, summarizes, and discusses topics of interest. The research is not original; rather, the authors look at other existing research articles on the topic. Secondary articles are useful for learning about a topic of interest and gaining a better understanding of the overall scope or limitations of the research on that topic.