Explanation

Box 1: Microsoft Power Platform
Power Platform combines the robust power of PowerApps, PowerBI, and Microsoft Flow into one powerful business application platform - providing quick and easy app building and data insights. Each component of the Microsoft Power Platform is built on the Common Data Service for Apps. Each component is dynamic by itself, but brilliant and masterful when combined.
The Microsoft Power platform brings all your data together into a common data model.
Box 2: Entities
An entity is a set of records used to store data, similar to how a table stores data within a database.
Reference:
https://community.dynamics.com/365/b/encloud9dynamicss365crm/posts/an-introduction-to-the-microsoft-powe
https://docs.microsoft.com/en-us/powerapps/maker/common-data-service/data-platform-intro