NAICS Industry Classification:
The United States Census Bureau created a classification system for business entities called the North American Industry Classification System (NAICS). Several company databases and industry research databases use these to organize their information, and it is useful to know these codes when you are looking for industry reports. These codes start at 2 numbers to identify broad industry group and move to 6 to identify specific industries.
315240 - Women's, Girls', and Infants' Cut and Sew Apparel Manufacturing
454110 - Electronic Shopping and Mail-Order Houses
SIC Industry Classification:
The Standard Industry Classification (SIC) System was developed to define businesses in the 1930's, but it has not been updated since 1987 when NAICS was developed. Some companies still use SIC codes, and they tend to used for historical research because NAICS only goes back to 1987.