Scholarly
Scholarly journals contain articles written by experts in academic or professional fields.
Professional
Usually published by a professional organization, professional journals contain articles about current issues and news relevant to professionals practicing within the field. Typically the articles/journal will be in a magazine-type format, with images and advertising. The articles also are relatively short, and generally do not include references at the end.
Peer-Reviewed or Refereed
Peer-reviewed journals publish articles that have been reviewed by experts in the field. These highly respected experts (peers, referees, reviewers) read the submitted article and decide if it is acceptable for publication.
If the article is acceptable, peer-reviewers may suggest changes or corrections. Peer-reviewed articles are also known as refereed articles; generally these are found in scholarly journals. Not all scholarly journal articles are peer-reviewed, however. One may occasionally find peer-reviewed articles in professional journals.
Need to know if your journal is peer-reviewed? Some of the library's databases will have a peer-reviewed limiter. Journal Finder will also tell you if a journal is peer-reviewed.