An academic article is a non-fiction composition written by a person, group of people or organization.
A journal is a periodical or magazine published at regular occurring intervals. A journal publishes a group of articles on a particular topic/subject. E.g, Accounting, Music, Science, Education
A database is an electronic directory that holds articles from published journals.
You can get articles that were published in journals that have been digitized (electronically formatted) and collected in the library's databases online:
A-Z Databases - https://libguides.lehman.edu/az.php
A peer-reviewed (refereed) article is evaluated by fellow specialists of research. This evaluation is done to assess an article's publication requirements and guidelines for publication.
A scholarly article is concerned with academic learning and research.