Private Company – A private company is one that is owned by an individual, family, or group of partners. The amount of information that private companies must report is limited, and much of that is confidential. Thus, it is often difficult to find much information on a private company. The best hope of locating information on a private company is through searching trade and popular magazines, major newspapers, the company's Web site, and by contacting the company directly.
Public Company – A public company is a company that issues securities or shares of stock for the public. Those who purchase these securities or shares become investors in and owners of the company. This process is regulated by the Securities and Exchange Commission (SEC), and public companies must file numerous financial and other reports with the SEC. Because these reports are public information, much data and information can be found when researching public companies. For more information, visit the SEC web site at http://www.sec.gov/index.htm.
Subsidiary – A company which is owned in whole or in part by another (parent) company. When researching a subsidiary, it is often advantageous to also research the owning company or the parent company. Sometimes the only information available for a subsidiary is that which is found within the parent company's annual report, press releases, and other parent company reports.
This content courtesy of RUSA/BRASS: BRASS Selected Core Resources - COMPANY AND INDUSTRY RESEARCH
NAICS Code - The North American Industry Classification System (NAICS) uses six-digit codes to identify an industry. The NAICS system is gradually replacing the SIC system. Many resources use these codes to identify a company’s activities, index companies by activity, and to define industry data and information. For more information on the history and structure of the NAICS, as well as to search for codes, visit the NAICS Association web site at http://www.naics.com/info.htm.
SIC Code - Standard Industrial Classification (SIC) codes are four-digit codes used to identify an industry. Many resources use these codes to identify a company’s activities, index companies by activity, and to define industry data and information. For information on the history of the SIC codes and information about its replacement, the NAICS, visit the NAICS Association web site at http://www.naics.com/info.htm. An excellent web site for a list of SIC codes and to search for a code is the OSHA site from the U.S. Department of Labor at http://www.osha.gov/cgi-bin/sic/sicser5.