NAICS stands for North American Industry Classification
System.
NAICS is an industry classification system that defines industries
based on the activities in which they are primarily engaged. The
system was developed by the U.S., Canada and Mexico to provide comparable
statistics across these three countries. It went into effect in
1997. Prior to that, each country used its own classification system.
The United States used the U.S. Standard Industrial Classification
(SIC) system.
The NAICS uses a six-digit coding system to identify a particular
industry and its placement within the hierarchy of this classifications
system. The first two digits designate the sector, the third designates
the sub-sector, the fourth designates the industry group, the fifth
designates the NAICS industry and the sixth designates the national
(U.S) industry.