Cloud NVR or Cloud Gateway or simply VXG Server is a software that runs on an on-premise computer and performs the following operations:
Connects to IP cameras in a local network.
Relays video to the Cloud.
Optionally records video.
If the server records video on-prem then it’s usually called Cloud Network Video Recorder (Cloud NVR). If it doesn’t record video and only relays video to the Cloud, then it’s usually called Cloud Gateway.