SIC Codes, or Standard Industrial Classification Codes, are numerical codes used to categorize businesses based on their primary activities. Established in the 1930s, these codes help government agencies, researchers, and businesses analyze economic data and trends. Each code corresponds to a specific industry, making it easier to identify and compare similar businesses. These codes consist of four digits, with the first two digits representing the broader industry group and the last two digits providing more specific details. For example, a code starting with "28" might relate to chemical manufacturing, while a code like "2834" would specify a particular type of chemical production.