Power BI Overview

Power BI is a collection of software services, applications, and connectors that work together to turn your unrelated sources of data into coherent, visually immersive, and interactive insights.

Your data may be an Excel spreadsheet, or a collection of cloud-based and on-premises hybrid data warehouses. Power BI enables you to connect to your data sources, visualize, and discover what's important, and share that with anyone.

See source: What is Power BI?