You will probably learn more about a company from its Web site than from a company directory, which is just a compilation of basic facts about many different companies. A company directory, in book form, is generally arranged alphabetically, much like an encyclopedia or dictionary. Many of these directories are available online and can be searched using the internal search engine on that site. By using these directories you will be able to learn what industry a company is in, what products and services they sell, where their regional offices are located, and who their parent company is.

Many online company directories charge a fee before they will grant a researcher access to their information. These are called proprietary databases, but you might also see them referred to as electronic databases or directories. You may be able to access these databases through your public library or through your college library at no charge if that institution has a subscription. Many libraries even allow their patrons remote access to the proprietary databases to which they subscribe. That means you can enter the directory through your library's Web site with your library card number and a username and password. Call the reference desk of your library to find out what resources they subscribe to and how to access them.