The components of RDS
It can't be done alone. Several basic components are needed for RDS to function, including a VM host (and host agent), a connection broker, a VM publishing service, a Web portal and a redirector.
These technologies rely on one another. The VM host runs a virtual machine on top of a hypervisor, like Microsoft Hyper-V, and the VM runs the desktop OS accessed by the remote user. For the user to retrieve the VM, the VM host must publish the virtual machine's existence using an agent.
But how does RDS know which VM a user should get? Well ...