While Power BI is often classified as a visualization tool, the reality is that Power BI is not a single tool but rather a collection of interrelated tools and services that form a complete business intelligence ecosystem of its own. This ecosystem spans the entire business intelligence spectrum, from data sources to modeling, analysis, and visualization. In addition, this ecosystem includes components that are specific to Power BI itself but also to other Microsoft technologies that interoperate with Power BI, as well as third-party integrations. This interoperation with other Microsoft tools and technologies as well as third-parties makes Power BI a formidable business intelligence platform whose value far exceeds that of more siloed business intelligence tools in the market.

While the Power BI ecosystem is vast and complex, this ecosystem can be broken down into the following categories:

• Core, Power BI-specific
• Core, non-Power BI-specific
• Non-core, Power BI-specific
• Natively integrated Microsoft technologies
• Extended ecosystem

The Power BI Desktop is a free, Windows-based application that's installed on a local desktop or laptop computer. The Power BI Desktop is the primary tool that's used to ingest, cleanse, and transform various sources of data, combine the data into models, and then analyze and visualize the data through the creation of calculations, visualizations, and reports. Once reports have been created in Power BI Desktop, they are often published to the Power BI Service for sharing and collaboration.

The Power BI Service is a cloud-based, software as a service (SaaS) online platform. Originally known as Power BI for Office 365, today it is often referred to as powerbi.com or simply Power BI. The Power BI Service can be used for light report editing as well as sharing, collaborating, and viewing reports. Some data sources can be connected directly from the Power BI Service, but the ability to model and analyze that data is limited.

Power Query is the Microsoft technology that provides data connectivity and transformation. This technology allows business users to access over 100 different sources and transform the data without using code. Data sources supported by Power Query include a large number of file types, databases, Microsoft Azure services, and third-party services. Power Query also provides a software development kit (SDK) that allows for the creation of custom connectors so that third parties can create their own data connectors that seamlessly interoperate with Power Query. Power Query is used within the Power BI Desktop, Microsoft Excel, Microsoft SQL Server Data Tools for Visual Studio, and the Microsoft Common Data Service (CDS) for Apps.

Data Analysis Expressions (DAX) is a programming language that consists of a collection of functions, operators, and constants that can be used to write formulas, or expressions, that return calculated values. Similar to how the Excel Functions or SSAS MDX help you create new information from data already in your model, DAX is the Power BI equivalent.

The on-premises data gateway is software that is installed on premises in order to facilitate access from the Power BI Service to on-premises data sources. This allows the Power BI Service to refresh data from one or more data sources housed within on-premises systems. The on-premises data gateway comes in two modes—personal and enterprise. Personal mode can only be used with Power BI, while enterprise mode can be used with Power BI as well as by Microsoft Flow, Microsoft PowerApps, Azure Analysis Services, and other Azure Logic Apps.

SSAS (Tabular) is an evolution of Microsoft's multi-dimensional cubes. This technology is available outside of Power BI within SSAS and Azure Analysis Services but is also fundamental to Power BI. Models that are built within Power BI are actually built using SSAS Tabular, and the Power BI Desktop runs a full instance of SSAS Tabular under the hood, so to speak. Thus, when building models in Power BI Desktop, you are actually building an Analysis Services Tabular model.

Microsoft AppSource, or simply AppSource, is a marketplace for finding apps, add-ins, and extensions to Microsoft software, including Office 365, Azure, Dynamics 365, Cortana, and Power BI. Within Power BI, AppSource hosts custom visuals that can be downloaded and added to Power BI reports that have been authored within the Desktop. These visuals are supported within the Power BI Service as well but cannot be used directly from within the Service.

Power BI Report Server is an on-premises technology that is a superset of SSRS. Similar in function to the Power BI Service, Power BI Report Server allows Power BI reports authored in Power BI Desktop and Excel to be published and viewed while remaining fully on premises. Because Power BI Report Server is a superset of SSRS, Power BI Report Server can also host paginated reports (.rdl).

Power BI Embedded is a system of REST APIs that can be used to display visualizations, reports, and dashboards within custom applications that serve customers that are external to an organization. Power BI Embedded is often used by independent software vendors (ISVs) and developers.

Power BI Mobile Applications are native Android, iOS, and Windows applications that are downloadable from the respective platform stores, Google Play, the Apple App Store, and the Microsoft Store. Power BI Mobile apps are touch-optimized for viewing and interacting with Power BI reports that are published to the Power BI Service.

Power BI for mixed reality is based on the Power BI Windows mobile app but has additional capabilities that have been designed to work with Microsoft HoloLens. The HoloLens capabilities allow data to be projected holographically within the mixed reality environment, and also have the ability to view and interact with reports and dashboards published within the Power BI Service.

Office 365 is Microsoft's ubiquitous line of subscription services, which includes traditional Office applications plus other productivity services that are enabled via the cloud (the internet). Central to Office 365 is the concept of a tenant, an organization's very own slice of Office 365. Power BI integrates natively with Office 365 so that when a user subscribes to Power BI, the email address is checked for existing Office 365 tenants, and if one exists, the Power BI user will be added to that tenant. If an Office 365 tenant does not exist, Power BI will provision a new Office 365 tenant, sometimes called a shadow tenant, and the Power BI user will be added to that tenant.

Excel incorporates many underlying Power BI technologies as native add-ins. These include Power BI Publisher for publishing Excel files to the Power BI Service, Power Map for map visuals, Power Pivot, which provides access to Power Query, and the same underlying data model used by Power BI (SSAS Tabular) and Power View for additional visualizations. Excel is also a first-class citizen within the Power BI Service and is called Workbooks.

Microsoft Flow is a workflow technology that has a native connector for Power BI that supports both triggers and actions. Triggers are based on the Power BI Service's data alerts, and actions support both streaming and non-streaming datasets in the Service. Flow is actually part of the same group of applications within Microsoft, that is, the Business Applications Group.

PowerApps is a form of technology from Microsoft that provides a native connector to Power BI, as well as a custom visual. In addition, Power BI tiles can be embedded into PowerApps applications. Finally, PowerApps uses Power Query technology as part of its Data Integration feature. PowerApps is also part of the Business Application Group within Microsoft.

The Microsoft desktop application, Visio, has a custom visual for Power BI that was built by Microsoft. This visual allows you to link data within Power BI to a Visio diagram as values or colors that are displayed within the Visio drawing.

SharePoint provides the ability to embed Power BI reports within SharePoint via a native Power BI web part.

Dynamics 365 provides the ability to embed Power BI visuals natively within Dynamics 365 reports and dashboards. In addition, Power BI has native connectors for Dynamics. Finally, there are a number of apps available for Dynamics in the Power BI Service.

The CDS is actually central to PowerApps, Flow, Dynamics 365, and Power BI. The CDS allows an organization to store and manage data from all of these business applications within a set of standard and custom entities. Entities allow an organization to create a business-focused definition of their data and use this data within apps. Power BI has a native connector for the CDS.

As we mentioned earlier, the underlying technology behind Azure Analysis Services and  SSAS Tabular is also part of Power BI. In addition, Power BI has native connectors for Azure Analysis Services. Finally, an instance of Azure Analysis Services is included with a Power BI Premium subscription.

Azure ML technologies are becoming pervasive within Power BI. This includes the ability to create Columns from Example within Power Query, as well as custom visualizations such as the Key Influencers visual that's available in AppSource.

Power BI Dataflows have native integration with Azure Cognitive Services. This allows Azure Cognitive Services to use Sentiment Analysis within Power BI.

One of the native outputs from Azure Streaming Analytics is Power BI. This allows you to stream data that's running through Azure Streaming Analytics and display it on Power BI's dashboard tiles.

As we mentioned earlier, Power BI Report Server is a superset of SSRS.

Report Builder is a venerable Microsoft tool for the creation of paginated reports (RDL). These reports can be published to a Power BI Premium instance and displayed within the Power BI Service.

Microsoft has created a number of APIs and SDKs that enable the creation of custom visuals, data source connectors, and automation. As a result, there is a large extended ecosystem of third-party custom visuals, connectors, apps, and add-on products for Power BI. In addition, Power BI integrates with a number of other non-Microsoft programming languages such as Python, R, and Scalable Vector Graphics (SVG).

The Power BI community is a large ecosystem of users focused on the education and use of Power BI within local communities. To find a Power BI user group in your area, go to https://www.pbiusergroup.com.

In addition to local user groups, there is a general community website that provides forums and galleries where Power BI users can get questions answered about using Power BI. To access this community website, go to https://community.powerbi.com.