Power BI is a collection of software services, apps, 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 lets you easily connect to your data sources, visualize and discover what's important, and share that with anyone or everyone you want.
Power Query
Power Query is the data connectivity and data preparation technology that enables end users to seamlessly import and reshape data from within a wide range of data sources.
Data Model
The Data Model is the cornerstone of Power BI. Data Models benefit from utilizing a multiple table design with relationships. Which reduces file size and increases performance.
Power BI Desktop
Power BI Desktop is a free application you install on your local computer that lets you connect to, transform, and visualize your data. Power BI Desktop is the main tool used to develop Power BI Visualizations.
Power BI Service
The Power BI service (app.powerbi.com), sometimes referred to as Power BI online, is the SaaS (Software as a Service) part of Power BI in which you publish and share reports.