Both DVR and NVR record and stream videos reliably, with NVR offering a higher quality of the video. So the main difference between the two systems is the scalability, the method of transmission of data and the type of cameras used. While NVR has an easier installation method, higher video quality and native audio support for cameras with mics, it tends to be more expensive than a DVR system. However, if you just need a straightforward security setup, a DVR will be satisfactory especially if you already have a preexisting coaxial cable setup from a previous security system.