NAICS stands for North American Industry Classification System. NAICS (rhymes with "rakes") is the system created by the Census Bureau to organize industries by what they do. A NAICS code can be 2 to 6 numbers long, and the longer the NAICS code, the more specific it is.
For example, 335 is the NAICS code for "Electrical Equipment, Appliance, and Component Manufacturing" whereas 335110 is the NAICS code for the much more specific "Automotive light bulbs manufacturing."
