OS Deployment supports machine based licensing, that is the number of workstation and server machines on which you want to perform deployment. Here the licenses are tied to the machine's MAC address and once you purchase a license for a machine, you can perform any number of deployments on that machine. Depending on the operating system, you need to have either a workstation or a server license. E.g., to perform deployment on 100 workstation machines, you need to purchase 100 workstation licenses.