| Term | Definition | |||||||||||||||||||||||||||||||||||
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| AC | In alternating current (AC, also ac) the movement (or flow) of electric charge periodically reverses direction. An electric charge would for instance move forward, then backward, then forward, then backward, over and over again. | |||||||||||||||||||||||||||||||||||
| ActiveX | ActiveX is a Microsoft-created technology that enables different software applications to share information and functionality. ActiveX only works with Microsoft applications and on Microsoft Windows. | |||||||||||||||||||||||||||||||||||
| AF(Auto Focus) | An ability by which the camera lens automatically adjusts its focus on the captured subject. | |||||||||||||||||||||||||||||||||||
| AGC | Automatic Gain Control, an electronic circuit which amplifies the video signal when the signal strength falls below a given value due to the lack the light on the image device. | |||||||||||||||||||||||||||||||||||
| Analog Camera | A conventional surveillance camera without USB or Ethernet connectivity. Analog surveillance cameras typically output analog composite video signals over coaxial cable. | |||||||||||||||||||||||||||||||||||
| Analog Video Output | Analog video output enables installers to monitor the camera output on a conventional video monitor. It's ideal for pointing the camera, setting the focal length and adjusting for lighting conditions. | |||||||||||||||||||||||||||||||||||
| Auto IRIS | A kind of iris, is used to adjust the amount of enter light, electrically controlled by the camera. | |||||||||||||||||||||||||||||||||||
| Auto White Balance | A feature on color cameras that constantly monitors the light and adjusts its color to maintain white areas. | |||||||||||||||||||||||||||||||||||
| AVI | Audio Video Interleave, a Microsoft multimedia file format. An AVI file contains both audio and video data in a standard container that allows simultaneous playback. | |||||||||||||||||||||||||||||||||||
| AWB | Automatic White Balance, is used in digital camera to automatically compensate the type of light (daylight, fluorescent, incandescent, etc.,) or lighting conditions in the scene. To make it normal for the human eye. | |||||||||||||||||||||||||||||||||||
| Back Light Compensation (BLC) | A feature on newer CCD cameras which electronically compensates for high background lighting to give detail which would normally be silhouetted. | |||||||||||||||||||||||||||||||||||
| Bi-Directional Audio (G.711/726) | This feature conveys real-time audio between an IP camera and the central office. This enables an attendant in the central office to have a conversation with a person at the camera location. The system requires microphones in both locations and an amplified speaker at the camera position. The G.711 and G.726 compression standards preserve network bandwidth, enabling telephone-quality audio at very modest bit rates. | |||||||||||||||||||||||||||||||||||
| Bit Rate | Is the number of bits that are conveyed or processed per unit of time, often in conjunction with Kbit/s or Mbit/s. | |||||||||||||||||||||||||||||||||||
| Bitmap | A storage method of digital image. A bitmap is created whenever an image is scanned and defines a display space and the color for each pixel or bit. It can then be saved as a JPEG, GIF or other type of file. | |||||||||||||||||||||||||||||||||||
| C Mount & CS Mount Lens | There are two main types of lenses used in security cameras. The C mount lens has a flange back distance of 17.5mm. The CS-mount lens has a flange back distance of 12.5mm. C mount lenses, therefore, have a longer focal distance. CS-mount became widely used because it is more practical for many of today's more compact cameras. Lenses are often supplied with a 5mm spacer ring (sometimes called a C ring) that allows a C mount lens to be used on a CS camera. Most modern security cameras are CS. | |||||||||||||||||||||||||||||||||||
| CCD | Charged Coupled Device, an electronic detector made of silicon that converts light energy into electronic signals. It is used in many digital cameras for image detection. | |||||||||||||||||||||||||||||||||||
| CCTV | Abbreviation of "Closed-Circuit Television" A television system in which video signals are sent only to monitors in a specific area (e.g. a building) Also called "video surveillance" | |||||||||||||||||||||||||||||||||||
| CGI | Common Gateway Interface, A set of rules that describe how a web server communicates with other (CGI) programs. | |||||||||||||||||||||||||||||||||||
| CIF | Common Intermediate Format, a video format used in analog video. The resolutions are 352x288 pixels for PAL and 352x240 pixels for NTSC. | |||||||||||||||||||||||||||||||||||
| CMOS | Complementary Metal-Oxide Semiconductor, one type of image sensor found in digital cameras. | |||||||||||||||||||||||||||||||||||
| Codec | A codec is a device or computer program capable of encoding and/or decoding a digital data stream or signal. Codecs can convert analog audio to digital and computer digital sound back to analogue audio. | |||||||||||||||||||||||||||||||||||
| Compression | Digital video pictures can be compressed with a number of techniques to reduce file size. These include: JPEG and JPEG-2000 (for still images), M-JPEG, MPEG and h.264 (for moving pictures). | |||||||||||||||||||||||||||||||||||
| D1 | D1 CCTV resolution is: NTSC 704x480, PAL 720x576 pixels | |||||||||||||||||||||||||||||||||||
| Day and Night IR Lens | The camera with this feature will automatically detect the level of ambient light and instantly adjusts the brightness by switching to Infra-Red (IR) black and white mode. | |||||||||||||||||||||||||||||||||||
| dB | Decibel widely used to measure the loudness of sound. The decibel is more generally a measure of the ratio between two quantities,and can be used to express a variety of measurements in acoustics and electronics. | |||||||||||||||||||||||||||||||||||
| DC | Direct Current is the type of electricity. All of the electric charges move in one direction. | |||||||||||||||||||||||||||||||||||
| DDNS | Dynamic Domain Name Service is a method, protocol, or network service that provides the capability for a networked device. It is used to resolve a well-known domain name to an IP address that may change frequently. It provides a persistent addressing method for devices that change their location or configuration. | |||||||||||||||||||||||||||||||||||
| DHCP | Dynamic Host Configuration Protocol (DHCP) is a network application protocol used to automatically assign a dynamic IP addresses to individual devices on a network. | |||||||||||||||||||||||||||||||||||
| Digital Input (DI) | A Digital Input will detect a voltage or no voltage condition, and generates a logical 0 or 1, high or low. It could be used to trigger an alarm or other events. | |||||||||||||||||||||||||||||||||||
| Digital Output (DO) | To trigger an output alarm. | |||||||||||||||||||||||||||||||||||
| DNS | Domain Name System is the internet system to translate names into IP addresses. | |||||||||||||||||||||||||||||||||||
| Dual Streaming | The ability of an IP camera to generate two streams of images simultaneously. | |||||||||||||||||||||||||||||||||||
| DVR (Digital Video Recorder) | A Digital Video Recorder is a generic term for a device that is similar to a VCR but records television data in digital format on a hard drive as opposed to a VCR tape. In an analogue CCTV system, a DVR is a general term for a box with analogue video inputs from cameras, a hard drive for recording, and often has software to allow for timer recording, motion detection, and much more. See NVR. | |||||||||||||||||||||||||||||||||||
| Encoder | An encoder is used to encode a bitstream into a form that is acceptable for transmission. Inside video cameras, that changes individual component signals into composite signals. | |||||||||||||||||||||||||||||||||||
| Ethernet | Ethernet is a family of frame-based computer networking technologies for local area networks (LANs). | |||||||||||||||||||||||||||||||||||
| F | Used to indicate the range of focal length, such as f 2.4~24mm. | |||||||||||||||||||||||||||||||||||
| Factory Default Settings | The original setting for a device when it was first delivered from the factory. Sometimes, it is necessary to completely reset the settings changed by the user to factory default settings. | |||||||||||||||||||||||||||||||||||
| Focal Length | The distance between a lens and its focal point; it usually expressed in millimeters. A system with a shorter focal length has wider fields-of-view.
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| FPS (Frame Rate Per Second) | In digital video applications, refers to the number of video images that can be captured, displayed, or recorded in a second. Also referred to as the 'frame rate' or 'refresh rate'. | |||||||||||||||||||||||||||||||||||
| FTP | File Transfer Protocol (FTP) is a standard network protocol used to exchange and manipulate files over an Internet Protocol computer network. | |||||||||||||||||||||||||||||||||||
| Full Duplex | A communications system between two points that supports simultaneous, two-way transmission. For example, a full duplex telephone connection would enable both parties to speak and be heard simultaneously. | |||||||||||||||||||||||||||||||||||
| Gateway | A gateway is a network point that acts as an entrance to another network. It is often associated with a router to furnish the path for packets in and out of the gateway. | |||||||||||||||||||||||||||||||||||
| GIF | Graphics Interchange Format, a standard format for compression of images. GIF is commonly used on the web because it employs an efficient compression method. | |||||||||||||||||||||||||||||||||||
| H.264 | An extension of the MPEG-4 family of audio/video compression standards that takes advantage of more recent technology to achieve higher compression "efficiency." | |||||||||||||||||||||||||||||||||||
| Half Duplex | A communications system between two points that only allows one-way transmission at any given time. For example, a half duplex telephone connection would only allow one party to speak at a time, requiring the other to wait. | |||||||||||||||||||||||||||||||||||
| HD-SDI | HD-SDI stands for High-Definition Serial Digital Interface. It is the common term for a high-definition digital video transmission standard known as SMPTE 292M. The SMPTE 292M standard is part of a family of Serial Digital Interface standards that use a coaxial cable to transport uncompressed digital video. | |||||||||||||||||||||||||||||||||||
| High Definition | A video system with up to six times the detail of standard definition. High definition uses a wide, 16:9 aspect ratio screen and a resolution of either 1920 x 1080 or 1280 x 720. | |||||||||||||||||||||||||||||||||||
| HTTP | Hypertext Transfer Protocol; is a request/response protocol between clients and servers. | |||||||||||||||||||||||||||||||||||
| HTTPS | Short for Hypertext Transport Protocol Secure, a method of protecting network traffic from unauthorized access by means of encryption. | |||||||||||||||||||||||||||||||||||
| IEEE 802.11 | A group of standard wireless specifications developed by the IEEE. It defines a wireless interface between devices to manage packet traffic and supports speeds up to 2Mbps. | |||||||||||||||||||||||||||||||||||
| IEEE 802.11b | The extension of 802.11, the wireless throughput boosts from the original 2Mbps of 802.11 up to 11Mbps. | |||||||||||||||||||||||||||||||||||
| IEEE 802.11g | The extension of 802.11b, it brings wireless throughput up to 54Mbps. | |||||||||||||||||||||||||||||||||||
| IEEE 802.11n | Increases wireless throughput to up to 150Mbps and operates on the 2.4/5GHz frequency. | |||||||||||||||||||||||||||||||||||
| IEEE 802.11ac | Increases wireless throughput to up to 866.7Mbps and operates on the 5GHz frequency. | |||||||||||||||||||||||||||||||||||
| Image Sensor | An image sensor is a device that converts an optical image to an electric signal. It is used mostly in digital camera and other imaging devices. Currently a modern one is typically a charge-coupled device (CCD) or a complementary-metal-oxide-semiconductor (CMOS). | |||||||||||||||||||||||||||||||||||
| Infrared (IR) | Infrared radiation is a radiation of a wavelength longer than visible light, but shorter than microwave radiation. The colour cameras can detect infrared radiation by the heat and capture it. It will filter the infrared radiation by IR-cut filter and prevent the distortion. Under low illuminance or night, the cameras will remove the filter and allow infrared radiation to hit the image sensor and produce images in black and white. | |||||||||||||||||||||||||||||||||||
| IP address | IP (Internet Protocol) is the main network layer protocol used on the Internet. It defines how information gets passed between systems across the Internet. | |||||||||||||||||||||||||||||||||||
| IP Broadcast | In IPv4 it is possible to send data to all possible destinations ("all-hosts broadcast"), which permits the sender to send the data only once, and all receivers receive a copy of it. | |||||||||||||||||||||||||||||||||||
| IP Filtering | A set of security rules that discard IP datagrams or permit them to pass. Filtering enables IP cameras to restrict access to selected IP addresses only. | |||||||||||||||||||||||||||||||||||
| IP Multicast | That is a method of sending Internet Protocol datagrams to a group of interested receivers in a single transmission. It is often employed for streaming media application on the Internet and private networks. | |||||||||||||||||||||||||||||||||||
| IP Unicast | It normally refers to a single sender or a single receiver, and can be used for both sending and receiving. Usually, a unicast address is associated with a single device or host. | |||||||||||||||||||||||||||||||||||
| IP Waterproof Rating (IP66 - IP68) | The IP rating means that product is protected against the ingress of solid object and water. Many cameras or camera housings are designed for outdoor use, and therefore need to be waterproof. The first digital is the protection against solids, and the second digital is the protection against water. | |||||||||||||||||||||||||||||||||||
| IR cut Filter | Infrared-radiation cut filer, is a color filter used in color CCD or CMOS, in order to block the infrared light and make the colors more realistic. | |||||||||||||||||||||||||||||||||||
| Iris | The circular aperture that controls the amount of light passing through to the camera's sensing element. | |||||||||||||||||||||||||||||||||||
| JPEG | Abbreviation of "Joint Photographic Expert Group", a process used to compress and store image. | |||||||||||||||||||||||||||||||||||
| Kbps | Abbreviation of "Kilobits per second", a unit of measurement for the speed at which data is transported via a communications connection. | |||||||||||||||||||||||||||||||||||
| LAN (Local Area Network) | Local Area Network; is a network that allows multiple computers or other devices to be connected to each other. In order to share data or a resource or file storage space. | |||||||||||||||||||||||||||||||||||
| LED | Light Emitting Diode, a semiconductor used to convert information from electrical to optical form, typically as an indicator light. | |||||||||||||||||||||||||||||||||||
| Lens | A lens is a device, usually made up by a piece of shaped glass. It is used to concentrate or diverge light. | |||||||||||||||||||||||||||||||||||
| Lux | A measure of visible light intensity taken at the surface that the light source is illuminating. (1 lux = 1 lumen/square meter) | |||||||||||||||||||||||||||||||||||
| MAC addresses(Media Access Control address) | Media Access Control address (MAC address) is a unique identifier assigned to most network adapters or network interface cards (NICs) by the manufacturer for identification. | |||||||||||||||||||||||||||||||||||
| Mbps | Megabits per second, a unit for network connection speed.
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| MBps | Megabytes per second, a unit for network connection speed.
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| Megapixels | A megapixel (MP) is 1 million pixels, and is a term used not only for the number of pixels in an image, but also to express the number of image sensor elements of digital cameras or the number of display elements of digital displays. | |||||||||||||||||||||||||||||||||||
| MJPEG (Motion JPEG) | Motion JPEG, is a video codec consisting of a sequence of individual JPEG images meaning that each video frame or interlaced field of a digital video sequence is compressed separately as a JPEG image. | |||||||||||||||||||||||||||||||||||
| Motion Detection | An in-camera or in-DVR application that allows the trigger of events such as recording, high-quality video streaming, and automated alerts to occur only when motion is perceived. Motion detection helps to optimize bandwidth and preserve storage space. | |||||||||||||||||||||||||||||||||||
| MPEG | MPEG refers to a set of standards for audio and video compression. The acronym MPEG stands for Moving Pictures Expert Group, a group formed by ISO to set these compression standards. Each compression standard is designed for a different purpose. | |||||||||||||||||||||||||||||||||||
| MPEG-4 | MPEG4 is a video and audio compression technology found in many IP network camera models. The MPEG4 compression standard aims to deliver superior image quality while optimizing bandwidth. | |||||||||||||||||||||||||||||||||||
| Multiplexer | This is a device that takes inputs from 2 or more video channels and combines them into one signal. This is often done by using time division multiplexing, which interleaves frames from each channel in such a way that they can be split out again. Frequency division multiplexing uses different frequencies to achieve the separation of the signals. | |||||||||||||||||||||||||||||||||||
| Network | Any number of computers that are connected with one another via different lines and share data and devices. | |||||||||||||||||||||||||||||||||||
| Network Video Recorder (NVR) | A Network Video Recorder (NVR) is a hardware box that receives video streams over a LAN or WAN and captures them onto hard disk in digital format. Recording and playback can be managed remotely using a PC. | |||||||||||||||||||||||||||||||||||
| NTP | Network Time Protocol, an Internet standard protocol used for synchronize the network device clock. | |||||||||||||||||||||||||||||||||||
| OSD (On Screen Display) | A method of displaying set-up information and/or instructions on a display monitor. | |||||||||||||||||||||||||||||||||||
| Pan | IP cameras with panning capabilities can move back and forth horizontally in order to monitor wider areas. In many cases a camera's panning functionality can be controlled remotely from a PC using video management software. | |||||||||||||||||||||||||||||||||||
| PIR sensor | That is an electronic device that measures infrared (IR) light radiating from objects in its field of view. PIR sensors are often used in the construction of PIR-based motion detectors. Apparent motion is detected when an infrared source with one temperature, such as a human, passes in front of an infrared source with another temperature, such as a wall. The term passive in this instance means that the PIR device does not emit an infrared beam but merely passively accepts incoming infrared radiation. | |||||||||||||||||||||||||||||||||||
| Power over Ethernet (PoE) | With Power over Ethernet, a network device, such as an IP camera, receives power and transmits video and data over a single Ethernet cable. This allows for flexible installation in locations where power outlets aren't readily available. | |||||||||||||||||||||||||||||||||||
| PPPoE | Point-to-Point Protocol over Ethernet, is a protocol for network devices to communicate by establishing a DSL link connection with the ISP. | |||||||||||||||||||||||||||||||||||
| Protocol | In computing, a protocol is a set of rules which is used by computers to communicate with each other across a network. A protocol is a convention or standard that controls or enables the connection, communication, and data transfer between computing endpoints. | |||||||||||||||||||||||||||||||||||
| PTZ | PTZ (pan/tilt/zoom functionality) is a feature available in many IP camera models. PTZ allows users to monitor large areas. Pan, tilt, and zoom functions can be controlled remotely so operators can follow activity and focus in on specific details. | |||||||||||||||||||||||||||||||||||
| QCIF | QCIF CCTV resolution is 176 x 120 pixels in size and is one quarter the size of CIF resolution. This resolution is typically used for remote viewing from a mobile device (cell phone). | |||||||||||||||||||||||||||||||||||
| RAID | Short for Redundant Array of Independent Disks. A storage system that protects valuable data from hard disk crashes. Because RAID redundancy places data bits on multiple drives, data can survive even if a drive fails. For redundancy, you need RAID level 1 and higher. | |||||||||||||||||||||||||||||||||||
| Resolution | The number of pixels displayed on the screen. This is defined by two numbers that indicates the number of pixels displayed horizontally multiplied by the number of pixels displayed vertically. | |||||||||||||||||||||||||||||||||||
| RS-232 | RS-232 is a communications standard for serial communications between devices. In CCTV, this can be communication between a controller and a surveillance camera. The RS-232 standard allows for the connection of two devices through a serial link, and is the protocal used for serial connections in computers. | |||||||||||||||||||||||||||||||||||
| RS-485 | Also referred to as EIA-485 is a communications standard for serial communication between devices. RS-485 allows for serial connections between more than 2 devices on a networked system. RS-485 is typically used as the protocol to allow computers and remote controllers to control the activity of cameras such as pan, tilt, rotate, and zoom operations. RS485 is an updated version of the original serial protocol, RS-232. | |||||||||||||||||||||||||||||||||||
| RTCP (Real-Time Control Protocol) | Real-Time Control Protocol; is used to monitor the session. It is mainly used to feed the streaming server with reception statistics from the client. The server may then decide to use these statistics (such as the numbers of lost packets, the delay from reception) to adapt its strategy. | |||||||||||||||||||||||||||||||||||
| RTP (Real-Time Transport Protocol) | Real-time Transport Protocol; is the protocol used to transport the multimedia stream to the client. It sends a packet to the network but cannot warrant that the packet will reach its destination. | |||||||||||||||||||||||||||||||||||
| RTSP (Real-Time Streaming Protocol) | Real-Time Streaming Protocol; is mandated to manage the streaming session. This is called the Internet Remote Control. It allows the client to know about available streams at a location, get stream parameters...etc. It also allows to PLAY, PAUSE, STOP, just what you generally expect from a remote control. | |||||||||||||||||||||||||||||||||||
| Samba | Samba provides file and print services for various Microsoft Windows clients and can integrate with a Windows Server domain. | |||||||||||||||||||||||||||||||||||
| Saturation | A measurement of chrominance, or the intensity of color in the video signal. | |||||||||||||||||||||||||||||||||||
| Sharpness | Sharpness describes the clarity of detail in a image. | |||||||||||||||||||||||||||||||||||
| Signal to Noise Ratio(SNR) | Signal to Noise Ratio (S/N Ratio) This is the ratio between the signal strength and the noise levels on an audio or video signal. | |||||||||||||||||||||||||||||||||||
| SMTP | Simple Mail Transfer Protocol (SMTP) is an Internet standard for electronic mail (e-mail) transmission across Internet Protocol (IP) networks. SMTP is specified for outgoing mail transport and uses TCP port 25. Refer from Wikipedia. | |||||||||||||||||||||||||||||||||||
| TCP | TCP enables two hosts to establish a connection and exchange streams of data. It guarantees that packets will be delivered in the same order in which they were sent. | |||||||||||||||||||||||||||||||||||
| Tilt | Tilt refers to an IP camera's ability to be directed up and down in a vertical plane. The camera lens can be aimed at a specific part of a scene, and in many cases the tilt can be controlled remotely. | |||||||||||||||||||||||||||||||||||
| TVL (TV Lines) | This is a measure of the resolution of a video device. The higher the number, the higher the resolution is. 380 TVL is considered medium resolution. 480 TVL or greater is considered high resolution. | |||||||||||||||||||||||||||||||||||
| UDP (User Datagram Protocol) | The User Datagram Protocol (UDP) is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. UDP uses a simple transmission model without implicit hand-shaking dialogues for guaranteeing reliability, ordering, or data integrity. Thus, UDP provides an unreliable service and datagrams may arrive out of order, appear duplicated, or go missing without notice. | |||||||||||||||||||||||||||||||||||
| UPnP | Universal Plug and Play; is a set of computer network protocols. It allows devices to be attached or removed from the system even with the power on. | |||||||||||||||||||||||||||||||||||
| URL | Uniform Resource Locator, is used to specify addresses on the World Wide Web. The first part of the address is protocol and the second part specifies the IP address or the domain name where the resource is located. | |||||||||||||||||||||||||||||||||||
| Vandal-proof | To completely protect the camera from external impact and make it ideal for video surveillance outdoors. | |||||||||||||||||||||||||||||||||||
| Varifocal Lens | A camera lens in which the focus is not fixed, it can be manually or automatically adjusted. | |||||||||||||||||||||||||||||||||||
| VGA | Stands for Video Graphics Array, a computer display resolution with a standard width and height resolution of 640 x 480 pixels. Other common DVR resolutions include:
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| Video Compression | It refers to reducing the quantity of data used to represent digital video images, and is a combination of spatial image compression and temporal motion compression. | |||||||||||||||||||||||||||||||||||
| Web Browser | A web browser is a software application that retrieves, presents and navigates information and resources on the World Wide Web. Common browsers are Internet Explorer (IE), Google Chrome, Mozilla Firefox, Safari (common on Apple devices), and Opera. | |||||||||||||||||||||||||||||||||||
| WDR (Wide Dynamic Range) | A WDR-enabled camera can record greater scene details, particularly from shadows to highlighted areas of the frame. It produces clear images even under backlighting, or where there are very bright and very dark areas simultaneously in a camera's field of view. | |||||||||||||||||||||||||||||||||||
| WiMax | Short for Worldwide Interoperability for Microwave Access, a broadband wireless | |||||||||||||||||||||||||||||||||||
| Wireless | In IP surveillance, connection methods that make it possible to install cameras in parking lots and other locations beyond the reach of Ethernet cables. Wireless technologies include 802.11 and WiMax. | |||||||||||||||||||||||||||||||||||
| WLAN | Abbreviation of "Wireless Local Area Network". | |||||||||||||||||||||||||||||||||||
| WPS | Wi-Fi Protected Setup (WPS) is a standard for easy and secure establishment of a wireless home network. WPS devices may use PIN, push-button, NFC (Near Field Communication) or USB methods for easily creating secure wireless connections, but only between compatible devices. | |||||||||||||||||||||||||||||||||||