What is an NVR and DVR in CCTV?
Shopping for CCTV can be confusing. One common question we get asked is “what is an NVR and what is a DVR?”
A brief overview of CCTV Video Recorders
NVR stands for Network Video Recorder and DVR is Digital Video Recorder. Think of Video Recorders as the brain of your CCTV system and the cameras are the eyes. The eyes see what is happening, it is sent into the brain where it is stored in the memory.
Even though both NVRs and DVRs are labelled as Video Recorders, they will only ‘record’ footage if you have a hard drive installed.
*Note: Not all recorders come with a hard drive so be sure to check this when buying one.
So, what is the difference between NVR and DVR?
On a technical level, the difference is how the data ‘seen’ by the camera is processed.
An NVR system will process and encode the footage at the camera end, and then streams it to the recorder.
A DVR system sends raw footage from the camera to the recorder where it is then encoded and processed by the recorder.
Most NVR systems use ‘IP Cameras’ whereas DVRs use ‘Analogue Cameras’.
NVR’s can be part of a wired or wireless system, whereas DVRs can only be as part of a wired system.
What do NVRs and DVRs look like?
The difference, as you’ll see in the image below is the connections on the back of the unit.
DVRs use a twist on metal connection known as ‘BNC’. NVRs use an Ethernet style connection like the one on your internet router, it is known as RJ45.
Due to the nature of RJ45 cable, it is possible to carry power and video down one cable. This is known as ‘POE’ or power over Ethernet. It means you only need one cable from your recorder to your camera and not a dual cable for video and power like most analogue systems. The recorder powers both itself and the cameras.
*Note: Advances in DVR technology have led to ‘POC’ or power over coax technology, which allows DVRs to power cameras in the same way that POE NVRs can.
Which is Better, an NVR or DVR security system?
Both CCTV systems have their pros and cons which I will list below. From there, you should be better equipped to decide which system is the best for you.
- Lower Price point due to less complex technology in the cameras
- BNC cable is multi platform meaning you can upgrade your system without having to rewire your property.
- More choice in products, analogue cameras generally work well even across different brands.
- Signal degrades after 90 meters making it unsuitable for properties with long distances between camera and recorder.
- Cable is thicker than RJ45 and more rigid. Installation can be more difficult.
- If the system is not POC enabled, you will need to power the cameras using an additional power supply and dual cables.
- IP cameras are more robust and feature rich than analogue, capable of very high resolution and transmitting audio.
- POE allows one cable to power and carry video to your camera.
- Ethernet cable is easier to route than its analogue counterpart. It is also more readily available.
- Wireless CCTV systems are available.
- NVRs generally have better video quality than DVRs even at the same resolution due to how the data is processed.
- More expensive than DVR based systems.
- Can be confusing to set up or add new cameras to the system.
Both systems record footage to a good standard and are reliable as security systems. DVR systems are cheaper and generally more straightforward. NVRs are easier to install and require less wiring. For most properties a DVR system would be enough, especially if you’re upgrading an older system. If you need something easier to install, more powerful or wireless, then an NVR security system would be ideal. It all depends on the security needs of your property and your budget.