The ultimate guide to DVR and NVR security camera systems

Choosing the right security camera recorder is key to setting up a successful video system. Whether you are building a camera system from scratch, or considering an update to your existing security system, you will need a recorder to manage the footage.

Security camera systems vary depending on the CCTV cameras, cables and recorders you choose. There are many different variations, but overall there are two systems: those with analog cameras and digital video recorders (DVRs), or internet protocol (IP) cameras, such as dome or bullet cameras, and network video recorders (NVRs).

Both DVR recorders and NVR recorders enable you to view and store digital footage. The main differences include: camera choice, cabling and installation, how they process video, and running costs.

In this article, you will learn the difference between NVR and DVR, and which of these systems is the best fit for your physical security planning needs. 

What is DVR (Digital Video Recorder)?

A digital video recorder, or DVR, is generally used with analog security cameras. Analog video signal needs to be digitally encoded before it can be stored, so a DVR camera recorder encodes the signal, stores it, and also decodes it for remote viewing on demand.

DVR system components: analog security cameras and coaxial cables

Digital video recorders convert analog video signal into a digital format. CCTV DVR systems tend to be analog cameras, connected to the security camera recorder via coaxial cables. Along with an analog camera, DVR recorder and coaxial cable, some more advanced hardware is needed to encode the signal. It is converted by a piece of equipment known as an analog-to-digital converter (ADC), also known as an AD encoder.

Types of video cable for DVR recorders

There are two kinds of coaxial cable that you can use to connect an analog camera with DVR recorder technology. The first are standard coaxial cables, which only transmit analog signal as a frequency. However, these DVR security cameras also need a power supply to work. It is possible to run power cables to analog cameras from a nearby power outlet, but there is a second cable type that offers a more streamlined option.

A siamese cable combines a coaxial cable and a power cable into one casing, reducing the hassle and mess of numerous cables. This type of coaxial cable supplies power to an analog camera, whilst also carrying the signal to the DVR camera recorder.

Coaxial cables can reach a maximum distance of 90m or 300ft in length; any longer than this and the signal begins to degrade, compromising the video quality. This is an important factor to bear in mind when considering the size and layout of your DVR system.

Both types of coaxial cable can be bulky, so consider where you plan to set up your analog security cameras; if it involves running cables around corners or through very tight spaces, IP cameras and more flexible ethernet cables might be a better choice. The section on NVR systems below describes this equipment in more detail.

How does DVR work?

As the diagram shows, DVR systems rely on a coaxial cable to transmit the raw data, or unprocessed video signal. This signal is not digital, and only becomes so when it is encoded in the digital video recorder. Once encoded, it can be stored or viewed.

A nearby power source is also needed to power the camera system; the power can either be carried by a separate cable, or by a siamese cable that can simultaneously supply power and transmit video.

It is not possible to transmit audio over DVR security systems unless the security camera recorder has audio input ports, and the camera system is able to record audio. These can be added to your system, but the number of audio streams you can record is limited to the number of audio input ports available on your DVR camera recorder.

There is a type of cable known as audio-over-coaxial cable, which simplifies installation and removes the need for multiple ports, cables and additional connectors. Using these cables can increase the number of audio streams transmitted to your digital video recorder, without being limited by the number of audio ports.

DVR system benefits and disadvantages

DVR security system pros:

• A DVR system uses analog security cameras. These are not the latest security camera system available, so they tend to be cheaper to buy – an important consideration if you are on a budget. Investing in a DVR recorder for cameras is a more cost-effective option.
• DVR systems are useful if you have an existing security system that you don’t plan to fully upgrade in the near future. It is possible to make affordable improvements to your existing system by changing features such as cables, connectors, encoders, and even the software you use to monitor video data. 
• Similarly, DVR systems are more versatile if you want to mix and match different CCTV camera types and brands.
• As video transmission is analog, the cybersecurity threat is far less than that of IP cameras and network video recorders, which use an internet connection to transmit video.

DVR security system cons:

• Thick coaxial cables are difficult to install in all sites – especially if you have tight spaces or sharp corners.
• With DVR security systems, you are forced to design your security camera system around certain constraints: nearby power outlets to power your cameras, and a maximum cable length of 90m/​300ft to preserve video quality.
• Analog cameras are better than they used to be, but video resolution like TVL resolution tends not to be as high as that of IP cameras. Similarly, if you want to stream audio from multiple cameras, you might find DVR security systems limiting.

If HD video quality is not a must-have, or you are on a tight budget, then a DVR system could be a good fit for your business. While not the most up-to-date option available in the market, they offer good value and flexibility for businesses with older systems who aren’t ready to invest in a fully upgraded NVR system yet.

However, if you are looking to install a video security system from scratch, you should bear in mind the limitations of DVR security systems: the need for a nearby power supply, bulky cables with a maximum length, and fewer options for HD video and audio transmission.

What is NVR (Network Video Recorder)?

What does NVR mean? It stands for network video recorder, and an NVR security system tends to be used with internet protocol, or IP cameras, vs. analog. These cameras record digital video data and transmit it over an internet connection.

What is an NVR security system? IP cameras, ethernet cables and wireless cameras

Unlike DVR systems, NVR systems work entirely in a digital format. NVR system components vary depending on the internet connection used to transmit data. If the connection between the IP camera and the network video recorder is wired, then you need power over ethernet (POE) cameras and ethernet cables. If the connection is wireless, then wireless IP cameras such as 360-degree panoramic IP cameras are all that is needed to send video to the NVR recorder.

Ethernet cables for DVR and NVR have some advantages over the coaxial cables used in DVR systems. They are thinner, making them much easier to install and fit around awkward spaces or tight corners. Unlike coaxial cables, the video data transmitted over ethernet cables is digital, so it can travel much farther without degrading.

An ethernet cable can simultaneously provide power and transmit signal, so you need only one cable instead of two. This makes for a more streamlined camera system whose layout is not determined by the nearest power source.

How do NVR systems work?

In an NVR system, cameras like fixed IP cameras or bullet IP cameras can record and process video data within the device itself. It is a digital video recording camera that can also handle audio. This encoded video and audio data is sent over WiFi or an ethernet cable to the NVR recorder, where it is stored for decoding and remote viewing.

Ethernet provides IP camera power supply, as well as transmits audio and video data all in one. Since IP cameras transmit video data over an internet connection, the signal does not degrade over long distances, which means there is no maximum cable length, as is the case with coaxial cables in DVR systems. Coaxial over ethernet cables are also more flexible, making them easier to install in awkward spaces.

With wireless security cameras, there is no need for an ethernet cable either to power the camera or to transmit data. Instead, the cameras are powered by a battery pack and video and audio transmission to the network video recorder takes place over WiFi. This makes installation very simple, but if the WiFi connection is not stable, there is a risk of losing video data.

Benefits and disadvantages of camera NVR systems

NVR security system pros:

• IP cameras and ethernet cables do not have the same constraints as analog cameras and coaxial cables. IP cameras – especially wireless cameras – can be installed over a much larger area without compromising video quality. Ethernet cables transmit video over an internet connection, so the signal will not degrade over long distances.
• An ethernet cable is thinner than a coaxial cable, making it ideal for hard-to-install areas where bulky cabling will not fit as well.
• IP cameras use more modern technology to provide digital footage. If you want HD video and audio, or even just better-quality video, then an IP camera system is the best choice for you.
• IP cameras also have in-built additional features that analog cameras are not capable of, such as remote pan-tilt-zoom (PTZ) cameras, smart motion detection, video analytics, license plate recognition, and more.

NVR security system cons:

• IP camera systems are more expensive than their analog counterparts – chiefly because the technology is better and newer. The upfront cost of NVR system hardware plus installation will be higher than a DVR system.
• NVR systems are not brand agnostic like DVR systems. Before investing in a suite of cameras, check the manufacturer and model are compatible with the network video recorder you plan to buy.
• Compatibility issues also make it harder to ​“mix and match” hardware, firmware, CCTV camera cabling, cameras and recorders. Be aware that any upgrades you plan to make to an NVR security system might not be compatible for a particular plug and play cable, and might need extensive testing. 
• On the subject of compatibility, check the ONVIF profiles of the cameras and NVR that you plan to buy. Whilst different manufacturers might not work together using their own protocols, using ONVIF, NVR and camera systems can integrate. 
• While internet connectivity makes transmission faster and more reliable, you should check your connection and bandwidth before installation. WiFi connections to wireless cameras are especially prone to disturbance, which could lead to lost footage.
• An internet connection also exposes your network to cybersecurity risks, so as well as checking your camera system is reliable, you also need to check your network security. Most IP cameras and network video recorders come with their own firmware and NVR software which should be regularly updated, as well as a standard login which should be changed immediately.

If you have a larger budget or are starting from scratch, NVR systems offer you much more choice, and better quality results. You are investing in the latest technology, which offers you more options to customize your video security system to your business needs.

DVR vs NVR security systems: which is better?

So, which is the best system to buy? When considering an NVR vs DVR system, security cameras should be your starting point. These are the key element of any video security system – the recording equipment will be determined by your digital video recording camera choice. 

NVR vs DVR security cameras

Technically ​“NVR cameras” or ​“DVR security cameras” are misnomers, because it is possible to use DVR for IP cameras, and vice versa (although this is unusual and more complicated to run). On the whole, IP cameras, such as Pelco IP cameras, are best for a CCTV NVR system, and analog cameras are suited to CCTV DVR systems.

So what is an ​“NVR camera”? NVR cameras need to have digital video functionality within the device, since network video recorders only record and store video – they do not process it. If you do want to set up an NVR camera system with analog cameras, you will need an analog to IP converter, which digitizes the signal before reaching the recorder. 

If you choose a DVR for security cameras, it is possible to use either analog or IP cameras. Using a digital video recorder for security camera video provides more options if you are integrating multiple camera types into one system. This is especially useful if you do not have the budget to invest in a full system upgrade, but still want the benefits of newer IP cameras. 

When using a DVR recorder, cameras might need different converters depending on whether they are IP or analog. Coaxial cables have BNC connectors on each end, which plug straight into the DVR and analog camera. IP cameras will need a LAN/​Ethernet to BNC converter if your DVR recorder does not have enough LAN/​Ethernet ports available. 

With the right connectors and converters, there is technically no difference between DVR and NVR cameras. Having a good understanding of how video is transmitted to each kind of security camera recorder will ensure that you can make either system work for you.

Do I need a DVR or NVR recorder?

NVR vs DVR: which is necessary for security cameras? Most camera network installers would say yes – but the answer depends in part on which cameras you use, and how many of them you want to monitor. 

Wireless IP cameras with a WiFi network connection and an SD card do not necessarily need a security camera recorder. If you have between one and three cameras which you check a handful of times over a device like your phone or tablet, then you might find that the manufacturer’s remote viewing app is enough for your needs. This isn’t the most practical option for most businesses and mostly applies to homeowners.

If you have a larger number of cameras that you monitor ²⁴⁄₇, then the most effective way to do this is by using a security camera recorder appropriate to your camera type, ensuring all the video data is streamed and stored. Generally, the more cameras you have, the more you will need a proper video security infrastructure to manage them.

NVR vs DVR security systems: which is best for my business?

Before diving in head first and buying a whole system, step back and consider what you want to achieve with your budget and current operations.

While the very best NVR camera system on the market might seem like the answer to all your security issues, if you don’t have the budget to buy and maintain it, or the operations to monitor it properly, then it would be a wasted investment. In this case, one of the cheaper NVR systems available might be better suited to your needs.

Perhaps your business is fairly new to video security and you want to see what kind of setup will work best. A DVR system might actually be preferable, even though it is less advanced. Setting up new processes, maybe even with new staff, might require a simpler, cheaper system first, just to get you started.

If you have a security consultant helping you create your security control center, or you have the budget and expertise to invest in the very latest digital video recording cameras and recording technology, then a cutting-edge NVR security system might be the perfect fit for your requirements.

As with any big investment, weigh up the pros and cons, as well as the business benefits and risks, before making your decision. Thorough research is the key to picking the right video recorder system for your security needs.