SlotStatus purpose

I am not clear about the slotStatus API purpose. The documentation says "When the contents of a slot are consumed, the device must call DRS using the SlotStatus endpoint".

1. I am not clear why a device needs to call the SlotStatus API. What action does DRS take when slotStatus is called? What happens if my device does not call SlotStatus when an item is consumed?

2. The slotStatus request body parameters include onHandQuantity, remainingQuantity and originalQuantity. Why are these quantities needed? Does DRS do some kind of inventory management?

Thanks

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