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