Data Source : Power BI supports vast range of data sources. For Web Application, Data source can be be SQL Server, Oracle, file data sources e.g flat file, Excel & CSV etc.
Power BI Desktop : Power BI Desktop is a client-side report development and authoring tool. All the Dashboards will be created & published by using Power BI Desktop. Application.
Power BI Service : The Microsoft Power BI service (app.powerbi.com), sometimes referred to as Power BI online, is the SaaS (Software as a Service) part of Power BI built on Azure Cloud platform. It is business analytics and data visualization service that enables anyone to visualize and analyze data with greater speed, efficiency, and understanding.
Power BI Report Server : The Power BI Report Server is similar to the Power BI Service. The only difference between these two is that Power BI Report Server is an on-premise platform. It is used by organizations who do not want to publish their reports on the cloud and are concerned about the security of their data. Power BI Report Server enables you to create dashboards and share your reports with other users following proper security protocols. To use this service, you need to have a Power BI Premium license
Power BI Gateway : Power BI gateway is act as an interface between On premise & Cloud environment. It is used to connect and access on-premise data via secured channel. Power BI Gateways are generally used in organizations where data is kept in security and watch. Gateways help to extract out such data through secure channels to Power BI platforms for analysis and reporting.