Correct licensing of applications and operating systems is not an easy task. Many vendors have special rules when transferring licenses to a multi-tenant cloud infrastructure. Make sure you understand the licensing rules of the vendor. If uncertain, discuss this with your vendor. It may prevent some nasty fines from the vendor for not respecting the licensing end user agreement.
Basically, two scenarios are possible for licensing:
You use licenses offered by the cloud vendor. This is the easy option. You pay the service provider a monthly fee for using the license and you are done. However, the availability of licenses is restricted. Windows Server will always be an option, along with SQL Server and SharePoint. Your service provider will not offer all the application licenses you are currently using.
Use your own licenses in Microsoft Azure. We will discuss this in depth.
When using your owned licenses in a public cloud, there are a couple of possible restriction...