A Digital Video Recorder (DVR) is a device that records video in a digital format to a surveillance hard drive. DVRs made specifically for CCTV Security Surveillance System applications record video signals from security cameras.
A Network Video Recorder (NVR) is a software program that records video in a digital format to a Hard drive or other mass storage device. An NVR contains no dedicated video capture hardware. However, the software is typically run on a dedicated device, usually with an embedded operating system. Alternatively, to help support increased functionality and serviceability, standard operating systems are used with standard processors and video management software. An NVR is typically deployed in an IP video surveillance system.
Difference between a normal hard drive and surveillance hard drive. While a surveillance hard drive forms a central component to the digital storage of surveillance video. It can be used in a DVR, NVR, Video Server or a Video Management System in order to work 24 hours a day and 7 days week.