It's a question that gets asked a lot when people are initially looking at security camera systems. Which is better, how are they different and which one should I use?
The first thing you need to understand is that they both serve the same function within a surveillance camera system. Both a DVR and NVR records the images coming from a camera and stores those images onto a hard drive for long term storage. They also organize the cameras and makes it easy to view them all on one screen without having to toggle between different cameras. Both NVR's and DVR's are capable of remote view, which allows you to view the cameras remotely from your smart phones, tablets and computers via an application. Lets first talk about them individually and then go into how to choose the proper recorder for your needs.
A DVR, which stands for Digital Video Recorder, has BNC connections on the back which is typcially attached to RG59 wire. This is considered legacy technology and most experts agree that it's obsolete. Manufacturers have made recent advancements which has prolonged the life of this method, but in my opinion they are just buying time. DVR's accept a video feed being produced by a camera, which is a live feed and is not compressed meaning you could plug the line directly into a TV and it will display the image. A DVR only accepts video signals and cannot provide power to the cameras, so there is often an external power box located near the DVR for power or you will need to find local power where the camera is mounted.
A Network Video Recorder or NVR for short, works completely different than how I just described. The first difference is the fact that it has RJ45 connections on the back, which are typically connected to a CAT5e wire. NVR's will often feature "POE" ports on the back, POE stands for "Power Over Ethernet" and will allow the system to not only receive the infomration from the cameras but also power them as well. This makes installing and maintaing the system extremely convienent and easy. The next difference is how the system receives and records the images. If you remember, a DVR accepts streaming live video from an analog camera, on the other side of things an IP camera, which is used with NVR's, breaks the images up into thousands of tiny pieces called "packets" and then transmits them through the wire to the NVR.
When received, the NVR reassembles those packets into the images that are displayed. Doing it this way offers some major advancements; first of all if a single packet is lost because of sudden interference on the wire you won't even notice any difference on the image quality. This makes the system incredibly reliable and resiliant. Since you are breaking the image up into thousands of data packets it also means you can utilize wireless technologies such as point to point antennas which is very reliable and the only true way to do wireless cameras. Finally the last obvious advantage is decentralized recording, meaning that the camera does not need to be plugged directly into the NVR to record. Since you do not need a wire running from the camera to the NVR this allows for the use of Network Switches and even native off site recording through the cloud.
Although an NVR and DVR both do the recordings one does not work in the others' stead. Everything from the connections to the method of recording is completely different. Here at Proactive Security Cameras we recommend IP cameras paird with an NVR as the preferred method of installing a surveillance system because of the advanced features, reliability, flexibility and technology available for these style of systems.
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