Power BI is a business analytics tool used by over 50,000 companies across industries like sales, marketing, finance, and HR. It allows for self-service analytics through data visualization capabilities and connecting to various data sources. Power BI features include fast time to market, interactive visualizations, and big data capabilities. It can help analytics teams address tasks like gathering and analyzing data from various sources and presenting visualizations to stakeholders. Training courses on Power BI cover real-world examples, applications of features, analysis techniques, and business exposure through mock-up creations.