The ICB uses a system of 11 industries, partitioned into 20 supersectors, which are further divided into 45 sectors, which then contain 173 subsectors.

The ICB is used globally (though not universally) to divide the market into increasingly specific categories, allowing investors to compare industry trends between well-defined subsectors. The ICB replaced the legacy FTSE and Dow Jones classification systems on 3 January 2006, and is used today by the NASDAQ,