Remote Desktop Gateway (RDG), previously known as Terminal Services Gateway, is a Windows Server component that provides routing for Remote Desktop (RDP). Rather then users connecting directly to an RDP Server, users instead connect and authenticate to the gateway. Upon successful authentication, the gateway will forward RDP traffic to an address specified by the user, essentially acting as a proxy. The idea is that only the gateway needs to be exposed to the Internet, leaving all RDP Servers safely behind the firewall.