Business intelligence (BI) involves collecting, structuring, and analyzing data to provide useful information for making strategic, tactical, and operational decisions. The key components of BI include gathering data from various sources, storing the data in databases or data warehouses, analyzing the data, and providing access to the analyzed data through reports, dashboards, and other tools. Popular BI tools are provided by companies like SAP, IBM, SAS, Oracle, Microsoft, and MicroStrategy and are used for applications such as analyzing customer behavior, sales forecasting, financial planning, marketing campaign optimization, and supply chain management.