A periodical is a publication that comes out periodically, such as a magazine, journal, or newspaper.
Keep in mind that a scholarly journal is aimed at an audience of scholars who study a particular field. Many scholarly journals are also peer-reviewed, but not all.
A trade periodical, often a magazine or newsletter, is a publication aimed at practitioners in a certain trade or profession that contains articles about trends, news, and practices in the field.
Some examples of trade periodical titles are American Libraries, Social Work Practice, Professional Nurse, and Farming Magazine.
A popular periodical, usually a magazine or newspaper, appeals to a popular rather than a scholarly or professional audience.
Some examples include Newsweek, Better Homes and Gardens, Ebony, and Rolling Stone.