Explanation:
Box 1: role-playing
We see that DimDate relates to FactOrderDetails in three ways: to the OrderDate, to the ShippedDate and to the RequiredDate.
Note: Role-playing dimensions
A role-playing dimension is a dimension that can filter related facts differently. For example, at Adventure Works the date dimension table has three relationships to the reseller sales facts. The same dimension table can be used to filter the facts by order date, ship date, or delivery date.
Box 2: filter the FactOrderDetail on OrderDate
The relationship between DimDate(Date) and FactOrderDetails(OrderDate) is the active relation.
Reference:
https://learn.microsoft.com/en-us/power-bi/guidance/star-schema