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Below is a glossary of terms we commonly explain to help you understand IP video technology.

AI Video Analytics

AI-based video analytics refers to the application of artificial intelligence (AI) and computer vision technologies to analyse and interpret video footage automatically. By using sophisticated algorithms, neural networks and machine learning, AI-based video analytics systems can detect, track, and understand the various objects, events, and patterns it sees within video streams. These analytics enable real-time or post-event analysis, providing valuable insights and actionable data for a wide range of industries and use cases. AI-based video analytics can be used for security and surveillance purposes, traffic monitoring, crowd management, retail optimisation and more, significantly enhancing efficiency and decision-making in these areas.

Some video analytics, whilst marketed as AI-based, may not include the use of true AI. Typically, video analytics created using machine learning or deep learning methods are not AI-based. These methods rely on training video analytics algorithms using thousands, sometimes millions of images and allowing the algorithm to tune itself based on these inputs.

Analogue CCTV cameras

Analogue, when applied to CCTV, refers to security cameras which output video signals in a waveform, rather than a series of 1s and 0s. Older CCTV cameras tend to use this as their primary form of video output. Some newer IP cameras offer this as a secondary output so that older monitoring equipment can be used, easing migration from analogue to digital IP systems.


Anti-ligature refers to design features and measures implemented to prevent the attachment of ligatures or hanging points in order to minimise the risk of self-harm or suicide in certain environments, such as healthcare facilities, psychiatric hospitals, or prisons.

Application Programming Interface (API)

In the context of CCTV, an Application Programming Interface (API) is a defined set of rules and protocols that enables integration between CCTV systems and other software applications, allowing for seamless control, data retrieval, and interaction with the surveillance infrastructure. Specifically, an API allows for a device to easily be controlled or programmed remotely, such as rebooting, or setting views, allowing for users to create their own programs to talk to, amend and control cameras and other devices. The Axis Communications 'VAPIX' API is a good example of this.

CCD - Charge Coupled Device

A Charge Coupled Device (CCD) is a type of image sensor and is basically the eye of your IP security camera. Is it a small, light-sensitive integrated circuit which translates the light which hits it into a digital electrical signal.

On the CCD there are thousands or even millions of tiny receptive cells. These cells react to the red, green, or blue light components and record each as a voltage. The voltage is then read by the camera, compressed, and then sent along the network.

CCD sensors are usually measured in physical dimensions. In IP CCTV cameras these are usually 1/4, 1/3 or 1/2 an inch. Larger sensors tend to give a better picture as they have a larger surface area to catch more light.

CMOS - Complementary Metal Oxide Semiconductor sensor

A CMOS sensor, when applied to IP surveillance cameras, is a device which converts light energy into electrical voltages which can be read by an IP camera and translated into images. In a similar manner to CCD sensors, CMOS sensors are made up of thousands or millions of light-reactive cells. Each reacts to a component of light; red, green, or blue. The amount of light on each cell is translated into a voltage which is read by the camera and translated into data. This is then compressed and sent across the network to the viewing computer which arranges the data back into its original colour and position, providing a picture.

CMOS sensors are a lot newer than CCD sensors and thus the technology is improving all the time. CMOS sensors also require a lot less power than a comparable CCD sensor. CCD sensors tend to offer a higher quality image than a comparable CMOS sensor, although CMOS image quality is progressing as time passes.

Guest user access

Another method of accessing an IP camera is by way of a guest user account.

This is a function found in almost every IP camera which allows you to log in and view the live images from your camera without having to enter a username or password.

The benefit of guest user access is that you can open an IP camera to visitors.  This allows you to embed the live image in a web page so you can use an IP camera as a streaming webcam attraction.

H.264 compression format

H.264 (or MPEG-4 part 10) is an emerging standard in IP video and IP CCTV.  It is a method of video compression which can dramatically reduce the bitrate of live streaming video without any reduction of image quality.

Side-by-side, the size of the data streaming from a camera using H.264 will be up to 80% less than MJPEG and up to 30-50% less than MPEG-4. This means that bandwidth load across the network is significantly reduced when using H.264 compression and storage costs will be lower when recording CCTV footage.

The downside of H.264 compression has been the increased hardware costs due to greater amounts of processing required by the camera. This has made the technology available in only the very high-end network cameras so far, but this is changing.  With the recent launch of the Axis M10 series we are now seeing the introduction of H.264 in entry-level IP cameras and we think that H.264 will fast become the standard video compression format of choice for all network cameras in the years ahead.

H.265 compression format

See H.264 above. They are essentially the same, other than H.264 is a more effective compression format leading to lower bandwidth and storage use with the penalty of extra processing to achieve this.

HTTP - Hyper Text Transfer Protocol

The Hyper Text Transfer Protocol is the protocol used by network devices such as IP cameras and PCs for transmitting information across the internet. The Protocol was designed by CERN in Switzerland in the late 1980s as an easy way of transferring text documents. The project grew rapidly and now almost every website in the world uses it.

IP cameras usually have a built-in HTTP server to ease configuration and viewing. This is what you see when you log into your camera. These usually use port 80, although most cameras allow this to be changed if necessary.

Interlacing (related primarily to analogue cameras)

Interlacing is a way used by IP camera manufacturers to speed up the refresh rate of their cameras.

An IP camera sensor is made up of a mesh of pixels. The colour value of each pixel is transferred to the computer as a series of numbers which the computer then interprets back into colours and outputs on your screen. However, in particular with megapixel cameras, there can be millions of pixels to retrieve, which can require a large amount of processor time, either slowing the camera down, or pushing the price up as more powerful processors need to be used.

Since IP cameras take many pictures per second, the time between images is very small, leaving very little time for objects to move significantly. With this in mind, interlacing was developed whereby instead of reading each line of pixels one after another, only every second line is read. On the first pass the camera will read lines 1, 3, 5, 7 and so on. Once the last line has been read, the camera returns and reads lines 2, 4, 6, 8 etc, meaning that each frame only half the image is read, saving time and bandwidth. This means the camera can achieve a greater frame rate without requiring more powerful hardware.

The downside with this is that since objects are moving between shots, the position of the objects in view will change between shots. With slow-moving objects this is fine, but with fast-moving objects such as cars or people, a tearing effect occurs along the edges of the object.


A JPEG is a way of storing images on a digital device such as IP CCTV cameras, digital cameras and mobile phones. JPEG is a compressed format, giving a greatly reduced file size compared to image dimensions. The compression is adjustable but greater compression rations will result in loss of data and as such grainier pictures.

JPEG stands for Joint Photographic Experts Group, who created the format when trying to produce a smaller file size for transmitting images across the internet. Most IP CCTV cameras support this format due to the reduced file size which helps to reduce bandwidth and hardware usage.


LightFinder is a technology, developed by Axis Communications, for their cameras. LightFinder technology is a feature incorporated into their IP cameras that enhances image quality in challenging lighting conditions by providing exceptional low-light sensitivity, allowing for clear and detailed video capture even used in dark environments.


MJPEG is short for Motion-JPEG which is a means of storing video footage from IP cameras and digital camcorders.

An MJPEG Movie consists of many JPEG images, one after another. Since JPEG is a compressed format, so too is MJPEG, providing a low file size when compared to image dimensions. Each frame of an MJPEG movie has no reference to the next, so inter-frame compression is not used, making MJPEG movies larger than similar MPEG movies. However, since there is no inter-frame compression the file size of an MJPEG movie will not change dependent on the complexity of the images used. This means the file size is a lot easier to estimate when looking at recording solutions.

MJPEG, being composed entirely of JPEG images, is a video-only format.  Should you require audio recording you may wish to use another codec such as MPEG or H.264.

Network Video

Network Video, when used in security surveillance applications (IP CCTV), refers to a system which allows live motion video to be broadcast over IP-based networks, such as a Local Area Network (LAN) or the Internet, for the purposes of live monitoring or recording.

Network video uses a computer network as the means of transporting video and audio data rather than the traditional point-to-point cabling you would associate with analogue CCTV. This allows your digitised video and audio streams to pass through the same Ethernet cables which may already will be run throughout your organisation and business.

Furthermore, because network video is digitised to travel along IP-based networks it can be viewed remotely from any computer in the world which has access to the Internet. This allows 24-hour surveillance of your property or business. Being purely digital also means the data is stored digitally and will retain its quality and colour and will not degrade over time in the same way as analogue recordings.

NVR - Network Video Recorder

A Network Video Recorder (NVR) is a digital device which sits on your IP CCTV network to receive live image/video streams and record them digitally to a hard disk.

An alternative to PC/server-based recording, the NVR offers a less complex installation, is easier to set up and has a user-friendly interface for day-to-day use. As the NVR is solely designed for IP CCTV surveillance, the embedded operating system is optimised to handle the maximum number of cameras the unit supports. This means that you can be confident that the NVR will be reliable, stable and perform as intended, unlike a PC/server based approach which has many variables that could affect performance.

Multi-site installations are simplified with the use of NVRs. If your organisation spans multiple locations, you can centralise the security monitoring to one location by linking an NVR at each location to management software. Most NVRs today offer live video monitoring too, and also allow remote access so a number of people can log in and view their cameras on the same machine simultaneously using secure logins.


Pixel is short for picture element and is the term used for each of the small dots of colour on a computer screen which make up a picture. It also refers to the small receivers on IP camera sensors which transfer the light received into data.

Each pixel has a colour value of red, green, and blue. Varying the values of these three colours will alter the overall colour of the pixel. With IP cameras, the sensor records the red, green and blue values for each of these pixels and then transmits the values to your computer, which then rebuilds them in an image on your screen.

Outdoor CCTV Surveillance

IP cameras can be installed in both indoor and outdoor locations giving you the flexibility to choose the right camera for your needs.

Outdoor IP cameras come in two distinct variations. They can either be suitable for outdoor use with the addition of an external enclosure (such as an Axis 214 or Panasonic BB-HCM580) or they can be placed outdoors with no additional protection (such as a Mobotix M22M-IT-D22 or Panasonic BL-C160).

External enclosures are normally rated against the ingression of solid matter such as dust, dirt etc. and against water penetration (rain, snow etc.). The rating is normally expressed as an IP number and the values attributed will give the overall protection rating of the enclosure. Most housings also come with fans and heaters and are thermostatically controlled to keep a reasonable ambient temperature, so the camera view doesn’t steam up with condensation in colder climates.

Cameras which require no additional enclosure benefit from being a lot more compact than traditional CCTV enclosures. This offers discreet outdoor surveillance. They are also much easier to install, normally supporting Power over Ethernet so they can be connected with a single cable with no need to hire an electrician to run power cables.

Remember, outdoor cameras can also be used for security around the home. There are small, unobtrusive, easy-to-install cameras which are ideal for monitoring your property, vehicles, garage, entranceways etc., and some have infrared lights or bright white LEDs to enable you to see better in low-light conditions.

SDK - Software Development Kit

A Software Development Kit or SDK is a library of code used for creating applications, usually on specific platforms, to work with a specific IP camera or range of IP cameras. With IP security cameras SDKs usually consist of code designed to access and retrieve images from a camera over the network or to alter settings. SDKs are similar to Application Programming Interfaces (API) in that they allow remote communication with IP CCTV cameras, but SKDs differ in that they are created to allow camera-native communication to be embedded into proprietary applications.

Included with an SDK is full descriptive literature describing how the code works and how it should be used and often includes working examples to help developers understand how to integrate the code with their own. SDKs tend to cover an entire range of devices but may contain code chunks which are specific to one particular model.

Most IP camera SDKs are very tightly controlled by the manufacturer, often requiring registration and the signing of non-disclosure agreements to protect their software and intellectual property.

See also API.

Tamper Alarm

The Tampering Alarm is an intelligent feature found on IP CCTV cameras which have a strong focus on security, such as tamper/vandal-resistant IP cameras. The kind of cameras which are designed to be installed in exposed locations where there is an active threat of people interfering with the device.

It’s easy to set up. Once activated the camera will notify you if it has been moved, obscured, covered or sprayed with paint.

The way it works is simple. When the camera is first turned on it will take a few seconds to examine the scene. After the examination process is complete the scene is locked and any alteration to the scene can cause an alert. This does mean however that if the light levels change drastically in a scene (such as turning on or off a light) then the camera likely will generate a tampering alert. Some cameras have the facility to ‘turn off alerts from dark images’ so that it isn’t affected by light changes but the downside of that is that it will no longer trigger an alarm if the camera is covered or sprayed, only if it has been moved.

Tampering Alarms are a useful tool which provide instant feedback when a camera has been compromised, something which could take a CCTV operator a lot longer to discover.


An Application Programming Interface developed by Axis Communications for interoperability between devices and software.

Wireless IP cameras

There are a few IP cameras available today which have wireless connectivity built-in as standard allowing them to be placed around the home or business without the complication of running Ethernet cable to each room.  Other IP cameras also offer wireless connectivity as an additional add-on such as a wireless card. There are a few true wireless IP cameras, other than those for the consumer market. Wireless can easily be disrupted both unintentionally (external factors) or intentionally (technical intervention) and so it is now seen as a secure and reliable means of getting security video onto the network by security professionals. This explains why Network Webcams stocks few wireless IP cameras.

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