Windows containers don't have the same licensing requirements as servers or VMs running Windows. Windows is licensed at the host level, not the container level. If you have 100 Windows containers running on one server, you only need one license for the server. 

What that means is, if your company currently uses VMs to isolate application workloads, you can save so much money by moving to containers. Removing the VM layer and running apps in containers directly on the server removes the licensing requirement for all of the VMs, and the management overhead for all those machines.