NAICS (rhymes with bakes) stands for the "North American Industry Classification System". It is a 6 digit decimal classification code system used to identify economic activity from the sector down to the industry level. Developed by the Office of Management and Budget of the Federal Government, it is used to collect, analyze and report on US economic activity.
Many business databases use NAICS codes as a search or a limit option. Businesses and marketers use NAICS to build lists of competitors or potential business clients.