If you're searching for a journal article on a particular topic, choose the Articles tab. 
The resources on this page focus on specific journal titles.
And while you could search for articles within one particular journal title, it would be terribly inefficient.
Databases found under the article tab will search thousands of journal titles at one time.
Image Source: Wikimedia Commons. 1799. Public Domain.
To efficiently search for information on a topic--choose resources that search hundreds or thousands of journals in one fell swoop. These resources may be found in the articles tab.