A network video recorder (NVR) is a software program that records video in a digital format to a disk drive, USB flash drive, SD memory card or other mass storage device.ideo on a DVR is encoded and processed at the DVR, while video on an NVR is encoded and processed at the camera, then streamed to the NVR for storage or remote viewing. Hybrid NVR/DVR security systems exist which incorporate functions of both NVR and DVR; these are considered a form of NVR.