A Database* is a computerized and structured set of data that can be manipulated and searched.
*Databases can be general or specific to a subject. For example, APA PsychNet focuses on Psychology but JSTOR includes academic journal articles from 75+ disciplines. Databases can contain one or multiple formats. Academic Search Premier has scholarly journal articles, magazine articles, books, and more, but Ebook Central only contains e-books.
Academic Search Premier
Examples Nature, JAMA, Cell, Shakespeare Quarterly, American Economic Review
Examples: To Kill a Mockingbird, Just Mercy, The Distance Between Us
Examples: New York Times, People, Time, National Geographic, Rolling Stone
Examples News clips, Photos, Music, Film
Databases contain information records about items. Some have citations only, some have the full text of articles, and some articles can be scholarly or not. When in doubt, ask a librarian!