(updated Nov 2019 for Power Automate)
Following the rebranding of Dynamics CRM to Dynamics 365, Microsoft has continued to evolve the product and along the way produced lots of new names.
This simple article aims to clarify possible confusions with naming.
The Power Platform
The Power Platform (note, it is written as two words) is a not a product in itself. To quote James Philips, Corporate Vice President, Business Applications Group, the Power Platform is:
"... a system that enables users to do three key actions on data that help them drive business: Analyze, Act, and Automate. We do this with Power BI, PowerApps, and Flow, all working together atop your data to help EVERYONE, from the CEO to the front-line workers, drive the business with data."
So the Power Platform is a collective term for other products in much the same way as Dynamics 365 is a brand name and not a specific product.
Power BI (again note the two words with a space) is a business intelligence tool. Quoting from https://powerbi.microsoft.com/en-us/:
"Power BI is a business analytics service that delivers insights to enable fast, informed decisions.
- Transform data into stunning visuals and share them with colleagues on any device.
- Visually explore and analyze data—on-premises and in the cloud—all in one view.
- Collaborate on and share customized dashboards and interactive reports.
- Scale across your organization with built-in governance and security."
Power Apps (this used to be a single word with no spaces, the space was added to the name in Nov 2019) is a cloud-based tool for building business apps. Quoting from https://docs.microsoft.com/en-us/powerapps/powerapps-overview:
"PowerApps is a suite of apps, services, connectors and data platform that provides a rapid application development environment to build custom apps for your business needs. Using PowerApps, you can quickly build custom business apps that connect to your business data stored either in the underlying data platform (Common Data Service) or in various online and on-premises data sources (SharePoint, Excel, Office 365, Dynamics 365, SQL Server, and so on)."
Power Automate (previously known as Microsoft Flow,(often shortened to just Flow) is a tool to create automated workflows between apps and services (including non-Microsoft ones) to get notifications, synchronize files and collect data.
UI flows (a preview feature) - is a robotic process automation feature which can record step-by-step actions and then replay them.
Common Data Service
OK, so having cleared up what the Power Platform is, what about the Common Data Service? This is another term that is often used and confused with the Power Platform.
The Common Data Service (CDS) is a service (no surprises there!) for storing and securing data from other applications. The apps in Dynamics 365 Customer Engagement (such as Sales and Service) store data in the Common Data Service.
If you have worked with Dynamics 365/CRM for a while, then you can think of the Common Data Service as what was the XRM platform of old (don't mix up the XRM platform with the Power Platform).
The Common Data Service is not a hidden or secret service for just Dynamics 365 apps. You can buy licenses for the Common Data Service so that you can build your own apps. The licenses are called PowerApps licenses, more details at https://docs.microsoft.com/en-gb/power-platform/admin/pricing-billing-skus
Common Data Model
The Common Data Model sounds very similar to the Common Data Service, so are they the same thing? Well, no. The Common Data Model (CDM), defines a set of data elements for business applications to use and share. This allows different apps to have a consistent representation of entities such as a contact or account. The idea is to get apps speaking the same language.
The Common Data Service stores data in conformance with the Common Data Model.
More details at https://docs.microsoft.com/en-us/common-data-model/
Separately from the above Microsoft sells a growing list of applications (Sales, Service, Field Service, Talent, Finance and Operations and more) under the Dynamics 365 brand. Many of these products (but not all) work on top of the Common Data Service and can work with Power BI, PowerApps and Power Automate.
Power BI, PowerApps, Power Automate, Common Data Service for Apps are purchasable products.
Power Platform and Common Data Model are concepts or collective terms.