Question: Does anyone know how we can differenciate Order Status And Order State ?

Answer: 
The “order state” and “order status” are usually mixed up since their names and functions are quite similar.

* 1,Order Status. All orders have an order status that is associated with a stage in the order processing workflow
* 1,An order state is a position of an order in the curent processing flow.
* 2,Magento Order State is used to define processing order
* 2,Magento Order Status is used by the administrator to know the exact order flow

[This article you can refer more about details](https://amasty.com/knowledge-base/what-is-the-difference-between-magento-order-status-and-order-state.html)
The order status is just a label for the order state. It doesn't represent any logic or workflow. 
You could even assign the "status" closed for pending payments. 

If you have PayPal, CC and Checkmo as Payment options, you might want to assign different order statuses for each of those when there's a pending payment. Like pending CC, pending Paypal etc.