The library catalog is a database that identifies where items are located in the library.
How do you search for items in the catalog? Most library catalogs allow you to search by author, title or subject. Some require you to use special commands or enter terms in a specific way.
Author: search last name first
If looking for books by: Vinton Cerf
Title: drop the first article (a, an, the)
If looking for the book: The Complete Internet User's Guide
Subject: use subject headings
If looking for books about: the history of the Internet
How do you find an article once you have a citation from a periodical index? After you gather a list of citations from a periodical index, check to see if your library owns that magazine or journal by searching for the title of the periodical in the library catalog.
If looking for this article: "Gossip on the web: Truth, lies and cyberspace." The Economist 351.8116 (April 24, 1999): 84.