Databases are collections of references to journal articles from many journals, chapters in books, reviews, conference proceedings,reports & in some cases, dissertations & theses.
Online databases are most useful for finding articles when you do not know in which journals articles are published.
In many cases databases include the full text of articles.
ACMDL: Digital Library
Current Contents: Social &Behavioral Sciences (SBS)
Inspec (incl. Supply chain ; Logistics)
LISA (Library & Information Science Abstracts)
WARC (World Advertising Research Center)