Business Statistics of the United States by Examples of industry specific Websites:
"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." Adopted in 1997, NAICS is a joint venture of Canada, Mexico, and the United States. Many databases and other reference sources use NAICS codes to organize data. This U.S. Census website includes the full 2017 NAICS Manual.
The Standard Industrial Classification System (SIC) , established in 1937, was superseded by NAICS. However, some databases still continue to refer to SIC codes.
