Overview

A library contains a wealth of information, including books, magazines, newspapers, videos, microfilm, and CD-ROMs. How do librarians keep track of all this? It takes organization and careful arrangement.

The Dewey decimal system is a classification system that libraries use to organize books. This system groups books together in broad categories. The broad categories are then broken down into subcategories. Each book is assigned a number that tells the category and subcategory in which it belongs.

The Library of Congress system is a different classification system. It uses letters, and then numbers, to group books.

The library's reference section holds general information sources, including encyclopedias, atlases, almanacs, yearbooks, and biographical dictionaries. Most libraries also offer Internet access, videotapes, audiotapes, DVDs, and CDs. All these sources can provide basic and reliable information.

Many libraries hold vast collections of periodicals, which, until recently, had to be searched for by using a printed index. Most periodicals are now in computer databases, which are relatively easy to search and navigate.