Is this a primary source?
When you are trying to identify primary sources in the sciences, you are looking for first-hand, contemporary, original research with direct evidence or data.
Primary sources in the sciences could be conference papers, dissertations, letters, lab reports, studies, or peer-reviewed scholarly work, all with original research. This work often includes an abstract, an introduction, methods, results, and discussion sections. A good way to identifying a primary source in the sciences is to check for a methods section in the article - if it's a primary source, the authors themselves were involved in the original research and will have included a methods section describing their experiment.
When you're looking for a peer reviewed source, you're looking for an original piece of research that has been published in an academic journal.
There are several tools that can help determine if an article is peer-reviewed.
Occasionally there are pieces in a peer reviewed journal that are not technically peer reviewed research articles, such as book reviews or literature reviews. However, if it is a research article (i.e., if it's original research with a methods section) in a peer reviewed journal, then the article would be considered peer reviewed.
Still not sure if your article is peer reviewed? Bring it to the library or chat with a librarian who can help you.