Whats the point of returning purchaseg?ranted and notprocessedyet?

I never saw a point on what returning these do, does robloxx read them?

After a person purcahses something like a developer product

I noticed them doing

    	return Enum.ProductPurchaseDecision.NotProcessedYet
	return Enum.ProductPurchaseDecision.PurchaseGranted

and i was wondering

When you return purchase granted, Roblox knows that the purchase went smoothly and it’s case closed. When you return NotGrantedYet, the callback will still fire until it’s granted, so Roblox makes sure the buyer received what they paid for.