Hi Nikhil,
Basically this is the model used as Software as License product by Amazon, it is per user based license maintained and controlled by Amazon. So you do not have to buy or agree the license agreement with Microsoft Clearinghouse.
Check the features and how it works, each license is assigned to the user based on the subscription process and if you do not want or client any hassles of managing the CALs etc this is a good model, but do check out the prices compared to the Microsoft CALs and Server cost for RDS if you go in that route.
Hope this helps.
JS
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