The Standard Industrial Classification (SIC) is a system used to categorize industries based on their primary business activities. Developed in the United States, it helps government agencies, researchers, and businesses organize and analyze economic data. Each industry is assigned a unique code, making it easier to track economic trends and conduct statistical analysis. SIC codes are often used in regulatory filings, economic research, and market analysis. They provide a standardized way to classify businesses, facilitating comparisons across different sectors. The system has been largely replaced by the North American Industry Classification System (NAICS), but SIC codes are still widely referenced.