When you use an online article index, it quickly scans thousands of issues of many different periodicals to find a match for your search terms.

An index will show you which periodicals have articles on your topic.

Otherwise, you would have to look through each issue of each periodical for articles on your topic.

Hey, can't I find periodical articles free online?

No, not really.The library subscribes to thousands of periodicals. You can only access them for free through the library.