The Standard Industrial Classification (SIC) system is a series of number codes that attempts to classify all business establishments by the types of products or services they make available. Establishments engaged in the same activity, whatever their size or type of ownership, are assigned the same SIC code. These definitions are important for standardization.

Beginning in 1997, the North American Industry Classification System (NAICS) replaced the older SIC codes. This six digit code is a major revision that not only provides for newer industries, but also reorganizes the categories on a production/process-oriented basis (SIC used a mixture of production-based and market-based categories).

This new, uniform, industry-wide classification system has been designed as the index for statistical reporting of all economic activities of the U.S., Canada, and Mexico.