A peer-reviewed article is a scholarly paper that was reviewed by experts in the field before publication. Because of this, peer-reviewed articles are often considered to be reliable and trustworthy resources, though you should always use caution.
A scholarly journal (also referred to as an "academic" or "peer-reviewed" journal) is like a discipline-specific magazine that publishes research in a given field. Scholarly journals typically release 2-6 issues per year, sometimes on specific topics. Beyond the publication date, each issue usually has a number associated with it. Students don't usually need to read a whole journal and will mostly access individual journal articles through databases.