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2MCCTV Glossary

Here you will find not only definitions for commonly used CCTV terms or surveillance technology "jargon," but also helpful images and links to related articles and/or products.  If there is a term you would like to see but it is not listed, please send an email to

Video Surveillance & CCTV Glossary terms


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 The capability of the surveillance system to send an alarm to the user’s phone/email by means of an integrated security system.


 An electrical signal transmitted by means of cable from a camera to a monitor. An analog camera is generally charged with voltage and current.



Angle of View
The maximum angle a camera can view through a lens.

Angle of View


An opening though which light travels into the camera lens. It controls the amount of light rays that reach the CCD.


Aspect Ratio
The ratio of the width of the picture to the height.


Auto White Balance 
The ability of a color camera to automatically balance flushes of white light into the aperture.


Automatic Gain Control
A function on the camera (and many electronics) that automatically balances the gain, or volume, of the signal, i.e. raise the volume if it is too low and lower it if too high.


Automatic Iris Lens
A camera lens that automatically adjusts to the lighting around it, by closing and opening the iris.

Varifocal Auto-Iris


A function on the camera that automatically terminates the loop-through once it reaches the last device on the chain of devices.






Backlight Compensation (BLC)
The ability of the camera to balance the lighting conditions when there is abundant light behind the object in focus.        A more advanced form is Wide Dynamic Range.                   
Check our article  Wide Dynamic Range to neutralize shadows

Wide Dynamic Range



The amount of data allowed to your computer over a specific period of time, usually expressed in bits per second (bps). 




British Naval Connector, a connector used between coaxial cable and an input/output port, either male or female, and couplingis complete with a quarter twist of the connector.          
Read our article about connectors.






C or CS Mount

A lens mount which attaches a lens to the camera. C mount lens are placed at 17.526 mm from the image sensor, whereas CS mount is placed at only 12.5 mm away. They are both 1 inch in diameter, and they produce the same image quality.



An image capturing device that utilizes light waves and displays the captured images (in a sequence) on a monitor.



Short for Category 5 cable, also known as Ethernet cable, transfers data from an IP network camera (sometime analog) to the monitor.



Cathode Ray Tube (CRT)
A vacuum tube which contains electrons that bounce off a fluorescent screen to display images from a camera. This is an outdated type of monitor.

Cathode Ray Tube (CRT)


A compact disc that allows for rewriting over saved data by means of CD-RW drive.


Charge-Coupled Device (CCD)
A chip in the camera that processes the signal of a picture as the camera receivs it. It produces high-quality images.  Super HAD CCD is a Sony specific CCD, and offers two times more image sensitivity than regular CCDs. 

Charge-Coupled Device (CCD)


Closed Circuit Television (CCTV)
The use of surveillance cameras to monitor and observe people, places, and things.


Coaxial Cable
A cable used to transmit analog signal from a camera to a monitor or DVR. It is named coaxial because of its components: a copper core and a woven copper shield.

Coaxial Cable


A device that compresses/decompresses (hence the name codec) the video feed from a camera.


Common Intermediate Format (CIF)
A common video resolution usually used with H.264 compression.  The images are 352 × 288 pixels.  4CIF is also used to display larger images (704 × 576).


Composite Video
A form of analog video format in which video feed and line and frame synchronization are combined onto one cable.



The feature on a DVR, or an IP camera, to compress an image, or make it smaller. Compression forms are MPEG4 and H.264.
Read about compressions.


Thedifference between color and brightness to help make a subject in an image more distinguishable.







Full resolution that displays 720x480 pixels (NTSC).


Decibel (dB)
The name of a logarithmic unit that measures the amount of sound.


DC Type Lens
Alens that uses power to help focus the lens.


The process of converting interlaced video into non-interlaced.  See interlaced video. 


Depth of Field
The area between the closest and further objects where everything in that area appears sharp and in focus.


Digital Signal
A signal that is expressed with binary numbers.


Digital Video Recorder (DVR)
A device that processes and compresses the images coming in from an analog camera and stores them on a Hard Disk Drive.

Digital Video Recorder


Dwell Time
The time lapse when switching between two cameras.

Dynamic Noise Reduction (DNR)
A feature on a camera that reduces the static, or noise, on an image, especially under low light.

Dynamic Noise Reduction


Dynamic IP Address

Provided by your ISP, it is an IP address that changes every time you log in to your computer.  This decreases internet security risks but is less reliable than a static IP address. 




Electronic Industries Alliance (EIA)
An organization that standardized equipment manufactured by companies and ensured they were compatible. 


A device that encodes/decodes video from an analog/IP camera and transmits it to a NVR/DVR.






A filter that blocks access to bad websites on your computer.



Frames per Second (FPS)
A measurement used for the DVR recording speed.  30 FPS is real-time recording. 










Example of 30 Frames Per Second


































Ground Loop
Video interference which causes horizontal lines on the monitor.  Could be caused by running the cable too close to a power line.
Read our article on video ground loop interference






Currently, the most advanced form of compression.  It saves space on your HDD while preserving image quality. 


Hard Disk Drive (HDD)
A device that stores digital data.  Ranges from 250 Gigabytes to 2 Terabytes. 


A switch located mainly on video recorders, which allows for switching the termination feature off.  This feature enables video signal transmission to other devices. 







Infrared (IR)
In the light spectrum, it comes below the color red, invisible to the naked eye.

Infrared (IR)


Infrared Cut Filter Removal (ICR)
An IR filter that is placed in front of the image sensor in a camera lens to remove infrared wavelengths that distort the image during daylight.  
Read our article on IR cameras

Infrared Cut Filter Removal (ICR)


Ingress Protection (IP) Rating
A code placed by National Electrical Manufacturers Association (NEMA) which describes the protection of an object against solid and liquid interference.
Read our article on IP Ratings.



Input/Output (I/O)
A device that can be integrated with a DVR or NVR and can be controlled, i.e. microphone, alarm, PTZ controller. 


Interlaced Video
Interlaced video is used to give the perception of doubling frame rate with an analog system while also conserving bandwidth. 


Internet Protocol (IP) Camera
A camera that sends and receives data over the internet.  It compresses videos itself, and can store footage directly onto HDDs.  Utilizes PoE for data transmission and power supply. 

Internet Protocol (IP) Camera


Internet Service Provider (ISP)
The company that controls/provides internet access to a consumer.






License Plate Recognition (LPR)
Software that has the ability to read and store license plates on cars.  It has the ability to count cars and when applied with a sensor, it can capture images of speeding cars or red-light violating cars. 


Light Emitting Diodes (LEDs)
A semiconductor of light. In CCTV, it is paired with IR to shed an IR light in low lighting conditions.

Light Emitting Diodes (LEDs) Light Emitting Diodes (LEDs)2


Loop Through
A feature in CCTV that enables transmission of video from one device to another through cables.  Only available on devices that feature Video In and Video Out. 

The measurement of minimum lighting required for a camera to record.  The smaller the lux, the darker the setting the camera can record in. 
Read our lux article







Motion Detection
A function on the camera that starts recording when it senses any motion.


Multiplexer (MUX)
A device that allows for the viewing of multiple analog cameras on one screen. The video feed is transmitted from a VCR.  A 2 camera multiplexer is called duplex, 3 triplex, and 4 quad.

Multiplexer (MUX)






National Television System Committee (NTSC)
An analog color television standard used in North America and some of South America. 
National Television System Committee (NTSC).jpg


Network Video Recorder (NVR)
Software that records video from an IP camera and stores it on a HDD or any storage device.  Usually integrated into a server, for the control of multiple cameras.  Video compression is typically done in the IP camera. 






Pan, Tilt, Zoom (PTZ)
A versatile camera that has the ability to pan (move side-to-side), tilt (tilt up and down), and zoom (in and out) onto certain objects. 


Accessories that can be connected to a computer, or I/O, i.e. monitors, keyboard, printer, mouse, etc. 


Phase Alternating Line (PAL)
An analog TV encoding system used in most of Europe, Asia, Africa, and South America. 
National Television System Committee (NTSC).jpg


Picture-in-Picture (PIP)
A feature that allows for the display of one large camera image on the screen surrounded by smaller camera images. 


Picture element, the smallest unit in an image. 


Port Forwarding
The process of opening ports on a router to allow incoming and outgoing traffic that is not defined in the routers set of rules.  This is put into effect when setting up remote viewing. 


Power over Ethernet (PoE)
The transmission of power to a camera over an Ethernet cable, CAT5 generally. 


Privacy Masking
A function on the camera that allows you to mask a frequently moving object, so it does not activate motion detection. 






Remote Viewing
A feature on DVRs and NVRs that allows the owner to view live and recorded footage from a laptop, smart phone, or tablet, as long as it has internet connection. 


The clarity of the image relayed by a camera.  The higher the resolution, the better the image quality. 






SÉCAM, or Séquentiel couleur à mémoire, is French for Sequential Color with Memory.  It is a French analog TV system. 

National Television System Committee (NTSC).jpg






TV Lines (TVL)
Or lines per picture height, is the number of horizontal alternating dark and light lines on a camera.  The higher the TVL, the higher the resolution, but the smaller the angle of viewing is.
TV Lines (TVL)






Uniterrupted Power Supply
Equipment that supplies power in the case of power failure, i.e. batteries or generator. 






Varifocal Lens
A lens whose focal length can be changed manually, has multiple focal lengths. 


Vertical Interval Switching
The seamless switch between two cameras, no time is elapsed. 


Video Cassette Recorder (VCR)
A device that records video and audio onto a VHS tape.  This is an outdated device that has been replaced with DVRs and NVRs. 
Video Cassette Recorder (VCR)


Video Graphics Array
A connector with three rows of 5 pins each, typically used with computers or hi-def TVs.  VGA is also a display resolution, 640x480 pixels. 
Video Graphics Array (VGA)


Visible Light
The light spectrum that is visible to the naked eye. 
Visible Light






A digital audio recording file.


White Light
The combination of all the lights in the visible light spectrum. 
White Light.jpg


Wide Dynamic Range (WDR)
The ability of a camera to compensate with multiple levels of light for the back light behind an object.





The ability of a camera to magnify a picture.
Read our article on digital vs optical zoom


Zoom Lens
A lens with the ability to zoom in and out without losing image quality.      
Zoom Lens