Standard Industrial Classification (SIC): SIC codes were replaced in 1997 by NAICS however some databases still reference SIC codes so it is important to know about both systems when doing business research.
The North American Industry Classification System (NAICS) is the standard used by Federal statistical agencies in classifying business establishments for the purpose of collecting, analyzing, and publishing statistical data related to the U.S. business economy. NAICS was developed jointly by US, Mexican, and Canadian economic agencies so business statistics can be compared among North American countries.