Differences between target selections

Hi there,

I was checking the Open API documents and got some confusions

From the “Discount API”, when you try to create a price rule, the target selection is “all” or “entitled”, and only two parameter can be used in this API

However, when I looked at the “cart API”, there are three parameters can be used, which are “all”, “entitled”

or “explicit”

Why there are differences between target selections? What does “explicit” mean and how to use it correctly?

Where do “explicit” coming from as there is no place to create a price rule with target selection of “explicit”?

Does anyone know the differences between them?

Found some info here https://shopify.dev/docs/api/storefront/2023-01/enums/DiscountApplicationTargetSelection