Jointly developed by the United Sta

Jointly developed by the United States, Canada, and Mexico, the North American Industry Classification System (NAICS) replaced the Standard Industrial Classification (SIC) system in 1997. NAICS distinguishes between establishments and enterprises.
NAICS classifies establishments into industries according to the primary business activity of the establishment. In the NAICS system, an establishment is defined as “a single physical location where business is conducted or where services or industrial operations are performed” (e.g., factory, store, hotel, movie theater, farm, office). An enterprise may consist of more than one location performing the same or different types of economic activities. Each establishment of that enterprise is assigned a NAICS code on the basis of its own primary business activity.
NAICS uses a two-digit through six-digit code to structure its categories into five levels of detail. The greater the number of digits in the code, the more narrowly defined the category. The five levels of categories, from broadest to narrowest, are sector (sig¬nified by the first two digits of the code), subsector (third digit of the code), industry group (fourth digit), NAICS industry (fifth digit), and national industry (sixth digit). The five-digit code is the level of greatest amount of comparability among countries; a six-digit code provides for more country-specific detail.
Although differences exist, the structures of ISIC, NACE, ANZSIC, and NAICS are similar enough that many of the categories from each of the different classification systems are compatible with one another. The U.S. Census Bureau has published tables showing how the various categories of the classification systems relate to one another