Explanation:

Box 1: Virtual Table
A virtual table is a custom table in Microsoft Dataverse that has columns containing data from an external data source. Virtual tables appear in your app to users as regular table rows, but contain data that is sourced from an external database, such as an Azure SQL Database. Rows based on virtual tables are available in all clients including custom clients developed using the Dataverse web services.
Scenario:
* First Up uses an on-premises system to manage current and historical patient data including medications and medical visits.
* The company plans to reference historical data in the existing system. The records held in these systems will not be migrated to the new solution except for medication information.
* The solution must provide a worker appointment booking system that can access worker historical job placement data.
* First Up staff members must be able to view and update worker records. They must be able to see current and historical job placement data on the same form in the new solution.
Box 2: Lookup (N:1)
Each worker can have many security clearances, so need a 1:N relationship.
Scenario: The solution must support tracking of security clearance information for a worker including the date, status, and certifying agency.
ce:
https://docs.microsoft.com/en-us/powerapps/maker/data-platform/create-edit-virtual-entities
https://docs.microsoft.com/en-us/powerapps/maker/data-platform/create-edit-entity-relationships