Glossary of Technical Terms and Definitions

Name: Adelaide Telefix
Address: South Road, Hilton, South Australia, Australia
Telephone: 0423 658 673
Price range: $$$

Item	Definition or Explanation
1080p	1080p is a high-definition video format with resolution of 1920 x 1080 pixels. The "p" stands for progressive scan, which means that each video frame is transmitted as a whole in a single sweep. The main advantage of 1080p TVs is that they can display all high-definition video formats without downconverting, which sacrifices some picture detail.
120Hz refresh rate	Some LCD and LED HDTVs have 120Hz refresh rates; these TVs employ sophisticated video processing to double the standard rate to 120 frames per second by inserting either additional video frames or black frames. Because each video frame appears for only half the normal amount of time, on-screen motion looks smoother and more fluent, with less smearing. It's especially noticeable viewing fast-action sports and video games. This feature is available on an increasing number of flat-panel LCD TVs.
240Hz refresh rate	240Hz refresh rate reduces LCD motion blur on LCD TVs even more than 120Hz refresh rate. 240Hz processing creates and inserts three new video frames for every original frame. Most "240Hz" TVs operate this way, but some models use "pseudo-240Hz" technology which combines 120Hz refresh rate with high-speed backlight scanning. An example of the pseudo-240Hz approach, which can also be very effective, is Toshiba's ClearScan 240™ technology.
3-2 pulldown processing	Sophisticated video processing common in HDTVs and progressive-scan DVD players. It corrects for artifacts and distortion that occur when film-based material (at 24 frames per second) is converted to video (30 frames per second), then de-interlaced to create a progressive-scan signal. For a more in-depth explanation, see our DVD Player Glossary.
3D TV	By adding a sense of picture depth and dimensionality, 3D TV's create a more engaging viewing experience that's similar to watching a 3D movie in a theatre. Like 3D movies, 3D TV requires that each viewer wears special glasses to see the 3D effects. 3D TV requires the use of wireless "active shutter" glasses.
Active shutter glasses	To see three-dimensional effects on a 3D TV screen, each viewer must wear a special type of 3D glasses called "shutter" glasses. Also called "active" glasses, these battery-powered liquid-crystal glasses are able to lighten or darken hundreds of times per second to alternately block out the left or right lens in coordination with the video frames flashing on the screen. The lenses aren't displaying images, just switching between dark and clear. To anyone not wearing shutter glasses, a 3D TV picture will look blurry. Active glasses are far more technologically advanced than the disposable 3D glasses handed out in movie theatres.
After image	Nearly any TV these days — LCD, plasma, or LED — has the ability to briefly retain an image. For example, if you were watching something in a squarish 4:3 aspect ratio, you might notice the faint outline of the black bars on the sides when you change to a 16:9 image. Unless you leave the exact same image up for a very, very long time (think days if not weeks), these "after images" are temporary. So if you do notice this kind of mild image retention in your TV, don't worry — in most cases, they'll disappear within minutes. Also see "burn-in."
Ambient light sensor	Will maintain a constant contrast level, even if the lighting in the room changes.
Analog Channel	A communications path that carries voice or video in analog form — as a varying range of electrical frequencies (See Analog Signal).
Analog Pass-Through	Digital converter box capability, which allows analog broadcast signals to pass through the converter box to be tuned by your analog TV.
Analog Signal	A type of signal that encodes voice, video, or data transmitted over wire or over-the-air that is commonly represented as an oscillating wave. An analog signal may vary in frequency in response to changes in physical phenomena, such as sound, light, heat, position, or pressure.
Analog Spectrum	A traditional range of frequencies used for radio and television transmission. This is a less-efficient and lower-quality system that uses Radio Frequency (RF) waves to transmit and display pictures and sound.
Analog Transition Date	The date set for the turnoff of analog broadcasting by TV stations. The final date we must transition from analog to digital broadcasting.
Analog TV	Analog television encodes television picture and sound information and transmits it as an analog signal (one in which the message conveyed by the broadcast signal is a function of deliberate variations in the amplitude and/or frequency of the signal). All systems preceding DTV (e.g. NTSC) are analog television systems. Analog technology has been in use for the past 50 years to transmit conventional TV signals to consumers.
Anamorphic video	Refers to widescreen video images that have been "squeezed" to fit a narrower video frame when stored on DVD. These images must be expanded (un-squeezed) by the display device. Most of today's TVs employ a screen with 16:9 aspect ratio, so that anamorphic and other widescreen material can be viewed in its proper proportions. When anamorphic video is displayed on an old-fashioned TV with a 4:3 screen, images appear unnaturally tall and narrow.
Antenna	Device designed to receive the radio waves broadcasted by television stations.
Anti-blur technology	A technology that reduces image "smearing" or "motion blur" that can sometimes occur with LCD or LED TV's. LCD televisions with anti-blur technology can deliver smoother, cleaner images than those without, particularly during fast-paced scenes. This anti-blur video processing is usually described as 120Hz refresh rate or 240Hz refresh rate. TV makers have their own proprietary names for anti-blur technology; examples include Sony's Motionflow™ and Samsung's Auto Motion Plus.
Artifacts	Unwanted visible effects in the picture created by disturbances in the video transmission or processing. Examples include "dot crawl" or "hanging dots" in analog pictures, or "pixelation" in digital pictures.
Aspect Ratio	The ratio of width to height in a video picture or other graphic image; describes the shape of a TV screen or program, not an actual inch measurement. 4:3 = standard "square" screen TV aspect ratio. 16:9 = typical widescreen TV aspect ratio.
Audio Return Channel	This feature is available on some 2010 TVs and audio/video components with HDMI 1.4 connections. A TV with Audio Return Channel allows a single HDMI cable to send the audio from the TV's built-in tuner "upstream" to a compatible A/V receiver, eliminating the need for a separate optical or coaxial digital audio cable.
Audio/video inputs	Using a TV's direct audio/video inputs to connect a DVD player, VCR, camcorder or other video component provides improved picture and sound quality compared to using the everything-on-one-wire RF antenna-style input. If your TV is old enough that it only has RF-type inputs, that's reason enough to consider replacing it, since many newer video components don't include an RF output.
Auto label	Identifies and labels the pre-set channels.
Auto tuning	Will automatically tune in the channels that an aerial can receive.
Backlight scanning	An anti-blur technology used in some LCD TV's. Typical LCDs use a fluorescent backlight that shines constantly, which can contribute to motion blur. LCD models with backlight scanning have a special type of fluorescent backlight that pulses at very high speed, which has the effect of reducing motion blur. Some recent TVs use backlight scanning along with 120Hz refresh rate for even greater blur reduction — this combination is sometimes called a 240Hz effect.
Baluns (or "matching transformers")	Additional equipment/devices needed to attach an existing Twin Lead antenna wire to a digital-to-analog converter box. Click here for more information.
Bandwidth	The maximum amount of information that can be transferred in a given amount of time. More detailed video requires more bandwidth. For example, high-def 3D video signals require much more bandwidth than standard-definition DVD video signals. This is why you need to have certain kinds of cables to pass high-quality video — not all cables are capable of carrying those higher bandwidths.
Barn Doors	This term is used in television production to describe the effect that occurs when a 4:3 image is viewed on a 16:9 screen. When this happens, viewers see black bars, or, "barn doors," on the sides of the screen.
BBE	Reduces distortion in the sound signal.
Bit Rate	The measure of how many bits of data are transmitted or received in a specified amount of time, such as kilobits per second; a low bit rate means lower quality and a smaller file size, while a high bit rate means better quality and larger files. Blu-ray
Bitrate	Measured as "bits per second," and used to express the rate at which data is transmitted or processed. The higher the bitrate, the more data is processed and, typically, the higher the picture resolution. Digital video formats typically have bitrates measured in megabits-per-second (Mbps). (One megabit equals one million bits.) The maximum bitrate for standard DVDs is 11Mbps; for over-the-air HDTV broadcasts, it's 19.4Mbps. Blu-ray discs have an even higher maximum bitrate of 54Mbps.
Black level	Describes the appearance of darker portions of a video image. Black is the absence of light, so to create the black portions of an image, a display must be able to shut off as much light as possible. Displays with good black level capability not only produce deeper blacks, but also reveal more details and shading in dark or shadowy scenes. Plasmas are generally known for having excellent black levels, since they can shut off pixels entirely. LED TVs with local dimming can also have very good black levels, since they can individually dim portions of the LED backlight behind the screen.
Brightness	This measures the quantity of light emitted from the television screen. A higher level of brightness will produce a bolder and more vibrant picture. An average brightness is 500cd/m2.
Broadcast Spectrum	An entire range of frequencies used for radio and television transmission.
Broadcasting	Using radio waves to distribute radio or TV programs, which are available for reception by the general public.
Burn-in	Screen burn-in was an issue for early plasma TVs. It could occur when a static image — like a non-widescreen 4:3 image with vertical black bars on the sides, or a scrolling stock or news ticker — remains on-screen for an extended period. These images could become etched into the screen's phosphor coating, leaving faint impressions.
CableCARD	Security card that Digital Cable Ready (DCR) TV owners must obtain from their cable company in order to view scrambled programming, such as premium services.
CableCARD™	A removable security card available from cable TV providers. It allows a TV with a compatible CableCARD slot to receive digital cable programming, including premium and HD channels, without using a separate set-top box. The FCC (Federal Communications Commission) began requiring service providers to make CableCARDs available as of July 1, 2004. Contact your local cable provider for details regarding the availability and costs of CableCARD-related services. See our article about Cable TV more details about CableCARDs.
Call Sign (Station)	In broadcasting and radio communications, a Call Sign is a unique designation that identifies a transmitting station. In some cases, they are used as names for broadcasting stations. A Call Sign can be formally assigned by a government agency or informally adopted by individuals or organizations, and it can be cryptographically encoded to disguise a station's identity.
Channel Scan	Channel Scan will search for digital broadcast channels that are available in your area; once the scan is completed, you will be able to tune to the digital channels received by your antenna.
Child Lockout/V-Chip	Allows parents restrictive authority over what their children watch. Child Lockout
Chrominance	The colour component of a video signal that includes information about hue (shade) and saturation (intensity).
Closed Captioning	Service allowing persons with hearing disabilities to read dialogue or the audio portion of a video, film, or other presentation, on the TV screen.
Coaxial	Coaxial inputs (sometimes just called "cable") provide a simple and common way to transmit video. Now coaxial inputs are mostly used for connecting a TV set to an antenna or cable system.
Coaxial Adapter	Device for connecting a coaxial cable to a TV with a Twin Lead cable connection port.
Codec	Term is short for "Coder-decoder." A codec is a device that converts analog video and audio signals into a digital format for transmission. It also converts received digital signals back into an analog format.
Colour Decoder	Translates colour-signal information from the source for display on all colour TV's.
Colour resolution (colour bit depth)	The colour resolution of HDTVs and other video gear is typically described as a colour bit depth such as "8-bit" or "10-bit." colour resolution indicates how fine the gradations can be between different shades of the same colour — it's a measure of colour accuracy. Nearly all consumer video equipment is 8-bit, and 8-bit resolution allows 256 possible shades. That's 256 each for the red, green, and blue primary colours. To calculate the total number of possible colours an 8-bit TV can reproduce, you multiply 256 x 256 x 256, which equals 16.7 million. Some TVs use 10-bit panels and video processing. That may not sound like much more, but 10-bit resolution means 1024 possible shades and over one billion total colours.
colour space	A "colour space" is a defined range of colours, and is usually associated with an industry standard. Examples of colour spaces that relate to television and video equipment include NTSC for analog video, and ATSC and x.v.colour for high-definition video. A wider colour space offers the potential for deeper hues. Few current HDTVs are even capable of reproducing the full NTSC colour space, let alone the wider ATSC colour space or the much wider x.v.colour colour space. When you see a TV's colour range expressed as a percentage of a colour space, it's almost always NTSC.
Comb Filter	Separates the chrominance and luminance from one another in composite-video connections; good comb filtering enhances fine detail, cleans up image outlines, and eliminates most extraneous colours.
Component video	The three-jack component video connection splits the video signal into three parts (one brightness and two colour signals). Compared to other analog video connections, component video has increased bandwidth for colour information, resulting in a more accurate picture with clearer colour reproduction and less bleeding. Component video is the only type of analog video connection that can pass high-definition signals, and provides better picture quality than S-video or composite video connections. Also see our connections glossary.
Composite Video	Also called "RCA" connectors, it is the most common way to connect peripherals and other components. It consists of one yellow connector for video and two audio connectors for "right" and "left." Composite connectors cannot transmit high-definition pictures. This means that, for HDTV, another connector option — such as HDMI or Component Video — must be employed.
Compression	Term that refers to the reduction of the size of digital data files by removing redundant and/or non-critical information ("data" being the elements of video, audio and other "information"). DTV in Australia would not be possible without compression.
Computer Input	This term refers to an input feature on some HDTV sets (like SVGA or VGA) that allows TV sets to be connected to computers.
Contrast ratio	Measures the difference between the brightest whites and the darkest blacks that a TV can display. The higher the contrast ratio, the better a TV will be at showing subtle colour details, and the better it will look in rooms with more ambient room light.
Converter Box	Also referred to as a "digital-to-analog converter box," this is a stand-alone device that receives, decodes, and converts over-the-air digital programming into analog. When connected to an analog television, it permits digital programming to be displayed in analog.
Cropping	When viewing widescreen format on an analog TV, the picture is cropped — i.e., black bars appear above, below, and on either side of the picture. This is done to maintain the original aspect ratio of the original picture source.
CRT (Cathode-Ray Tube)	A CRT ("picture tube") is a specialized vacuum tube in which images are created when an electron beam scans back and forth across the back side of a phosphor-coated screen. Each time the beam makes a pass across the screen, it lights up a horizontal line of phosphor dots on the inside of the glass tube. This beam rapidly draws hundreds of these lines from the top to the bottom of the screen, creating the image.
Datacasting	Also known as "enhanced TV," this is digital programming that provides additional features to viewers (with program material or non-program-related resources) such as the ability to download data (video, audio, text, graphics, maps, services, etc.) to specially equipped computers, cache boxes, set-top boxes, or DTV receivers.
DBS	Digital Broadcast Satellite. TV programming delivered via high-powered satellite. Signals are transmitted to a small dish (usually 18-24 inches across) mounted outdoors.
DCR	Digital Cable Ready TV. Also referred to as "Plug-and-Play," this is a DTV or other device for digital cable customers that plugs directly into the cable jack and does not require a separate set-top box to view analog and unscrambled digital cable. Used with a CableCARD, it can receive scrambled programming such as premium services.
Decoder	A device or program that translates encoded data into its original format — i.e., it decodes the data.
Deep colour	A colour resolution standard associated with high-definition TVs and video gear that include HDMI 1.3 connections. Deep colour supports 10-bit, 12-bit and 16-bit colour bit depths, up from 8-bit, which is the current standard for consumer video. All earlier versions of HDMI supported 8-bit colour. (Because video is based on three primary colours, you'll sometimes see Deep colour described as 30-bit, 36-bit and 48-bit.) A higher colour bit depth enables finer gradations between different shades of the same colour, for smoother gradients and reduced colour banding.
De-interlacing	The process of converting an interlaced-scan video signal (where each frame is split into two sequential fields) to a progressive-scan signal (where each frame remains whole). De-interlacers are found in HDTVs and progressive-scan DVD players. More advanced de-interlacers include a feature called 3-2 pulldown processing.
Digital	Describes a new, more efficient method of storing, processing and transmitting information through the use of computer code. Digital can also refer to the circuitry in which data-carrying signals are restricted to one of two voltage levels, corresponding to logic 1 or 0.
Digital audio output	A connection found on HDTVs and HDTV tuners for sending the Dolby Digital soundtrack of HDTV broadcasts to an A/V receiver with Dolby Digital decoding. These days, many TVs feature an optical digital audio output for this purpose. Some newer TVs also have a feature called "Audio Return Channel" that lets you send audio back to your receiver via HDMI.
Digital Channel	A communications path that handles only digital signals. All voice and video signals have to be converted from analog to digital in order to be carried over a digital channel. In regard to the DTV Transition, this is the corresponding digital channel number used after the channel has transitioned.
Digital comb filter	Separates combined colour and black and white picture information to provide a sharp picture.
Digital Monitor	Digital monitors are TV sets that can display a digital signal, but lack an integrated tuner (unlike an integrated digital TV set), and thus cannot receive a digital broadcast signal without an additional set-top box.
Digital Signal	A signal that takes on only two values — off or on — typically represented by "0" or "1." Digital signals require less power but typically more bandwidth than analog, and copies of digital signals can be made exactly like the original.
Digital Tuner	A digital tuner serves as the decoder required to receive and display digital broadcasts. It can be included inside a TV set or in a set-top box.
Digital-to-Analog Converter Box	Also referred to as a "converter box" or a "digital converter box," this is a stand-alone device that receives, decodes, and converts over-the-air digital programming into analog. When connected to an analog television, it permits digital programming to be displayed in analog.
Direct-view TV	A general term for non-projection types of TVs, which include conventional tube TVs and flat-panel plasma and LCD TVs.
DivX	Compressed video format based on the MPEG-4 standard that enables a feature-length movie to fit on a CD-ROM.
DLNA	DLNA, short for Digital Living Network Alliance, is a collaboration among more than 200 companies, including Sony, Panasonic, Samsung, Microsoft, Cisco, Denon and Yamaha. Their goal is to create products that connect to each other across your home network, regardless of manufacturer, so you can easily enjoy your digital and online content in any room.
DLP™ (Digital Light Processing)	A projection TV technology developed by Texas Instruments, based on their Digital Micromirror Device (DMD) microchip. Each DMD chip has an array of tiny swiveling mirrors which create the image. Depending on the TV's resolution, the number of mirrors can range from several hundred thousand to over two million. DLP technology is used in both front- and rear-projection displays.
DMA	Designated Market Area. A term used by Nielsen Media Research to identify an exclusive geographic area of counties in which the home market television stations hold a dominance of total hours viewed. There are 210 DMA in the U.S.
Dolby Digital 5.1	It boasts 5 separate channels, plus a sixth bass (hence the 5.1). Particularly suitable if you watch a lot of DVDs, you can also enjoy great sound on your Xbox or Playstation.
Dolby ProLogic	Most programmes broadcast this way. Featuring a five speaker system - left, right, centre and two mono speakers - you'll be able to enjoy the benefit.
Dolby ProLogic II	Similar to the ProLogic, but with a fuller rear channel range. It also works on two modes; 'movie' or 'music', for an enhanced sound experience.
Dolby® Digital	A form of multi-channel digital sound, it provides efficient encoding and noise reduction for high-quality surround sound — technology used in movie theaters and upscale home theater systems that enhances audio. Home theater components with this technology work in conjunction with a "5.1-speaker" system (five speakers plus a low-frequency subwoofer) to produce true-to-life audio that draws the listener into the onscreen action.
Downconversion	All digital TV display technologies have screens with a fixed number of pixels for displaying images. If a video source has a higher resolution than the screen's resolution, the TV will automatically downconvert the video signal to fit the screen. Downconversion reduces image detail, but downconverted pictures can still look very sharp. A good example is a 1080i HDTV broadcast displayed on a 720p TV.
DTV (Digital Television)	A general term for the digital broadcast TV standard, which replaced the PAL analog broadcast system. DTV comes in two basic flavors: widescreen, high-quality HDTV (High-Definition Television) with Dolby Digital audio, and medium-quality SDTV (Standard-Definition TV).
DTV Tuner	Allows the set to receive over-the-air HDTV broadcasts without having to attach a set-top box.
DVI	Digital Video Interface. A high-quality digital connector. Similar to HDMI and sometimes with HDCP, DVI can digitally transmit uncompressed, high-definition video, preserving perfect picture quality. Unlike HDMI or Firewire, DVI requires a separate audio connection.
DVR	Digital Video Recorder. A device that records video in a digital format to a disk drive or other memory medium within a device. The term includes stand-alone set-top boxes, Portable Media Players (PMP) and software for personal computers, which enables video capture and playback to and from disk.
DVR (Digital Video Recorder)	Digitally records video to a disk drive or other memory medium within a device and offers pause and rewind control over live broadcasts.
Dynamic backlighting	Found on many LCD TVs, this feature dynamically adjusts the brightness of the backlight in response to the picture content of whatever you're watching, to improve picture contrast and reduce power consumption. It helps the TV display both bright outdoor scenes and dark indoor scenes with greater accuracy. Use of dynamic backlighting contributes to the very high "dynamic contrast ratio" specs provided by TV makers.
EAS	Emergency Alert System. This is designed to provide the President with a means to address the American people in the event of a national emergency.
EDTV	Enhanced Definition TV. A better digital television transmission than SDTV with at least 480p (progressive), in a 16:9 or 4:3 display and Dolby® digital surround sound. The quality of most progressive scan DVDs and players is 480p.
EDTV (Enhanced-Definition Television)	A virtually obsolete class of televisions, generally flat-panel LCD or plasma, that displays signals in 480-line progressive-scan (480p) mode. 480p screen resolution is superior to standard analog TV (480i), but not as sharp as true HDTVs (720p or 1080p).
Electronic program guide (EPG)	Provides an on-screen listing of available channels and program data for an extended time period (typically 36 hours or more). Examples of program guides include subscription services like TiVo® and free guides like TV Guide® On Screen.
Emergency Video Description	Video descriptions are a way to inform people who are blind or have other vision disabilities of what is happening on the television screen. Video description is the insertion of verbal descriptions about the setting and/or action in a program when information about these visual elements is not contained in the audio portion of the program. These descriptions supplement the regular audio track of the program.
Emitter (for 3D TV)	An important part of a 3D TV system is the "emitter" that precisely controls the timing of the active shutter glasses. The emitter communicates with the glasses wirelessly via infrared beams. "3D-ready" TVs include a built-in emitter, while "3D-capable" TVs require that you add an outboard emitter box.
Energy Star® compliant	A certification for consumer electronics products indicating energy efficiency. The Energy Star program was introduced by the EPA (Environmental Protection Agency) in 1992, and set standards for product power consumption in "standby" mode. (When a component is switched off but still plugged into an AC power source, it continues to draw a small amount of power in standby mode to keep circuits active and ready for quick turn-on.) In November 2008, the EPA created the more stringent Energy Star 3.0 specification, which requires energy efficiency when products are in use, as well as when they are in standby mode. Products that meet the new spec are up to 30% more energy efficient than previous models.
EPG	Electronic Program Guide. An interactive list of upcoming TV programming that can be transmitted along with a DTV program.
Ethernet port	An Ethernet port on a TV enables a connection to a home network and/or the Internet. What you can do once you're on the network varies by model. Some TVs will let you play music or videos from your computer, or stream music or movies from services like Pandora® or Netflix®. See Internet-ready TVs for more info.
Fastext	Updated version of Teletext that uses coloured keys on a remote as shortcuts to particular pages.
Field	In interlaced-scan video, each complete frame is split into 2 sequential fields, each of which contains half the picture information. One field contains the odd scanning lines, and the other field the even lines.
Firewire	See IEEE 1394.
Flat Panel TV Sets	Thin, lightweight TV sets that can be hung on a wall. Current flat panels (also called "flat screens") use LCD or Plasma screen technology.
FPS (Frames Per Second)	The number of individual still pictures that pass by every second to create a moving image; the higher the number the more seamless the flow of images.
Frame	In moving picture media, whether film or video, a frame is a complete, individual picture.
Frame rate	The rate at which frames are displayed. The frame rate for movies on film is 24 frames per second (24 fps). Standard NTSC video has a frame rate of 30 fps (actually 60 fields per second). The frame rate of a progressive-scan video format is twice that of an interlaced-scan format. For example, interlaced formats like 480i and 1080i deliver 30 complete frames per second; progressive formats like 480p, 720p and 1080p provide 60.
Freeview	A free digital service offering over 30 channels through an integrated digital television or a separate set top box.
Front Projectors	These are TV sets that create the image on a small display, and then enlarge it by projecting it onto a wall or stand-alone screen (much like a movie theater). Front projectors tend to be dimmer than direct flat panels or CRTs, and often require the room to be dark to be able to see the image clearly.
Gain	Measures the light-reflecting ability of a projection screen. The higher the number, the greater the amount of light reflected back to the viewer(s).
Ghosting	A visual phenomenon in digital displays when an image moves faster than the display can redraw it, leaving a trail of former versions of the image in the wake of the redrawn image; as LCDs evolve, faster pixel-response times are reducing the ghosting problem.
HDCP	High Definition Content Protection. Technology used to prevent piracy of high-quality uncompressed video, primarily over DVI connections.
HDCP (High-Bandwidth Digital Content Protection)	HDCP encryption is used with high-resolution signals over DVI and HDMI connections and on D-Theater D-VHS recordings to prevent unauthorized duplication of copyrighted material.
HD-DVD (High-Definition Digital Video Disc)	High-density discs designed to hold HD video; can hold approx. 3 times as much video as a standard DVD.
HDMI	High Definition Multimedia Interface. A high-quality digital connector. Similar to DVI and sometimes with HDCP, HDMI can digitally transmit uncompressed high-definition video and audio on the same cable, preserving picture and sound quality.
HDMI-CEC	A remote control protocol that is an optional part of the HDMI spec — CEC stands for "Consumer Electronics Control." Available from HDMI version 1.2a on, HDMI-CEC allows multiple HDMI-connected components to be operated from a single remote control without any special setup or programming. HDMI-CEC is a 2-way communications system, and up to 10 devices can be controlled in a system. Each electronics manufacturer calls this feature something different: Panasonic uses EZ-Sync, Samsung Anynet+, Sony BRAVIA Theatre Sync, Toshiba CE-LINK, LG SimpLink, etc.
HDTV (High-Definition Television)	Often mistakenly used as a generic description of all digital television, HDTV specifically refers to the highest-resolution formats of the 18 original DTV formats. Although there still isn't 100% agreement among manufacturers, retailers, journalists, etc., only 1,080-line interlaced (1080i) or 720-line progressive (720p) broadcasts are generally considered to be true HDTV. 1,080-line progressive (1080p) is not an official HD broadcast format, but it is found on high-definition Blu-ray discs and some satellite TV movie broadcasts. And 1080p is now an established standard for HDTV screens.
HDTV Monitor	A TV set with the inputs and capability to become an HDTV with the addition of an HDTV tuner, HD cable set-top box, or HD satellite receiver.
HDTV Tuner	A device capable of receiving and decoding HDTV signals. HDTV tuners can either be built into a TV set (called an Integrated Digital TV Set) or be a stand-alone device, such as a set-top box.
HDTV-Enabled	Any TV that has a built-in tuner allowing the display of HDTV signals without a separate tuner or set-top box.
HDTV-Ready	Any TV that can display HD formats when connected to a separate HDTV tuner or source; usually able to receive analog broadcasts, but not over-the-air HDTV signals.
Hertz (Hz)	A measure of frequency. One Hertz equals one cycle per second. In video, Hertz is used to describe a frame rate in frames per second. For example, you'll often see 24-frames-per-second video at listed as "24Hz."
Horizontal Resolution	Number of vertical lines or pixels that can be resolved from one side of an image to the other; varies according to the source.
Household	All of the people who occupy a housing unit. A housing unit is a house, an apartment, a mobile home, a group of rooms, or a single room occupied as separate living quarters. Separate living quarters are those in which the occupants live separately from any other people in the building and who have direct access from the outside of the building or through a common hall.
IDTV	A TV with an integrated digital tuner.
IEEE 1394	A way to transmit compressed data and video between components on one cable. Also called Firewire or I-link, IEEE 1394.
Integrated HDTV Tuner	Allows the set to receive over-the-air HDTV broadcasts without having to attach a set-top box.
Interference	Unwanted electrical signals or noise causing impairments in the video signal.
Interlace Scan	A way to scan vertical lines onto a TV picture by scanning all the odd lines first, then filling in the even lines. The fields are aligned and timed so that, with a still image, the human eye blends the two fields together and sees them as one. Interlace scanning allows only half of the lines to be transmitted and presented at any given moment.
Internet-ready TV	TVs labeled "Internet-ready" can connect to your home network to access online content. For example, a growing number of Internet-ready TVs let you play movies from services like Netflix®, BlockBuster™, or Amazon Video On Demand™. Keep in mind that you won't be able to browse the Internet the way you do on your computer — you'll only be able to access specific sites and information based on software included in your TV. Different TV makers provide access to different Internet sites and services, and sometimes these capabilities can be enhanced by firmware updates that the manufacturer provides. Besides movie services, common examples include weather, news, social media updates, and sports scores.
Keystone correction	Keystoning is a form of video image distortion that occurs with front projectors if the centerline of the projector's lens is not perpendicular to the screen. Keystoning results in an image which is shaped like a trapezoid rather than a rectangle — the top of the picture is wider than the bottom, or the left side is taller than the right, for example. Most front projectors include "keystone correction" to correct this distortion. Some models have vertical keystone correction, while others include both vertical and horizontal correction. Although keystone correction allows greater mounting flexibility, it is a form of processing which usually has a slight softening and dimming effect on the picture.
LCD (Liquid Crystal Display)	Liquid Crystal Display technology is one of the methods used to create flat-panel TVs, and is also used in some projectors. Light isn't created by the liquid crystals; a "backlight" behind the panel shines light through the display. The display consists of two polarizing transparent panels and a liquid crystal solution sandwiched in between. An electric current passed through the liquid causes the crystals to align so that light cannot pass through them. Each crystal acts like a shutter, either allowing light to pass through or blocking the light. The pattern of transparent and dark crystals forms the image.
LCoS (Liquid Crystal on Silicon)	A projection TV technology based on LCD. With LCoS, light is reflected from a mirror behind the LCD panel rather than passing through the panel. The control circuitry that switches the pixels on and off is embedded further down in the chip so it doesn't block the light, which improves brightness and contrast. This multilayered microdisplay design can be used in rear-projection TVs and projectors. TV makers use different names for their LCoS technologies — Sony uses SXRD™, while JVC uses D-ILA™ or HD-ILA™.
LED (Light Emitting Diode)	An LED is a semiconductor diode that typically emits a single wavelength of light when an electric current passes through it. Different colours can be generated based on the material used; common colours include red, green, blue, and white.
LED-LCD TV	A term sometimes used for LCD TVs that use an LED backlight instead of a conventional fluorescent one. An LED backlight improves contrast and delivers a wider range of colours, for a more lifelike picture. TVs with LED backlights also generally consume less power than those that use fluorescent backlights.
Letterboxed	A method for displaying the entire picture as seen in a movie theater on a TV screen. The resulting image width is much greater than its height. On an old-fashioned TV screen with 4:3 aspect ratio, letterboxed videos appear with horizontal black bars above and below the image. You will often see these black bars when watching movies on a widescreen TV, too. To learn more about aspect ratios and ways to deal with those black bars, see our aspect ratio article.
Light output	Measures the amount of light produced by a video display, and is an especially important spec for projectors. Expressed in "lumens" or "ANSI lumens," with a higher number indicating greater light output, which results in a brighter picture.
Local dimming	A feature found on some LED-backlit TVs that allows them to dim or even completely shut off different sections of the LED grid independently. These TVs can accurately display both light and dark portions of an image at the same time, for greater contrast and a more lifelike picture. See our video on LCD backlighting for more info.
Lumen	The unit of measure for light output of a projector. Different manufacturers may rate their projectors' light output differently. "Peak lumens" is measured by illuminating an area of about 10% of the screen size in the center of the display. This measurement ignores the reduction in brightness at the sides and corners of the screen.
Luminance	Portion of a TV signal that controls brightness; usually expressed as cd/m2 or candle brightness per square meter; the higher this number, the better.
MATV	Master Antenna. Common or master antenna system in apartment buildings, condominiums, high-rises, co-ops or other Multiple Dwelling Units (MDU) through which residents receive local TV stations.
Mbps (Megabits Per Second)	Measure of networking bandwidth or data transmission speed, expressed in millions of binary bits per second.
Megahertz (MHz)	Equal to one million Hertz. Video signal bandwidth is typically expressed in megahertz.
Memory Card/SD Slot	Will enable you to plug your memory card, taken from your digital camera or camcorder, straight into your TV and playback all your files in style.
Microdisplay	A general term covering several different technologies used in digital rear-projection TVs and projectors. These displays produce large images; the "micro" refers to the postage stamp-sized image chips that create the images. Microdisplay types include DLP, LCD, and LCoS. For a comparison of rear-projection microdisplay types, and details on how each technology works, see our Choosing a Big-screen Projection TV article.
Monitor	A Monitor is simply a display device that is incapable of receiving digital broadcast programming without additional equipment.
MPEG	(Moving Picture Experts Group) A set of standards for compressing multimedia files. MPEG-1 is used in CD-ROMs. MPEG-2 is used for a broad range of formats, including DVD, HDTV, and surround sound; MPEG-3 was merged into MPEG-2. MPEG-4 is a standard for low-bandwidth video and multimedia.
Multi system TV tuner	Will allow the television to be viewed in some other countries.
Multicasting	DTV technology that allows each digital broadcast station to split its digital bandwidth into two or more individual channels of programming and/or data services (For example, on Channel 7, you could watch sub-channel 7-1, 7-2, 7-3 or 7-4).
Multi-Channel Digital Sound	Feature of DTV that permits numerous streams of sound to be transmitted for a given program, providing stereo, surround sound, and even other languages.
Must-Carry	The legal obligation of cable companies to carry the analog or digital signals of over-the-air local broadcasters.
Native Resolution	Specific resolution that a TV set — whether integrated or not — or a monitor, is designed to display. All other resolutions must be either up-converted or down-converted for display.
Network	A communication system consisting of a group of broadcasting stations that all transmit the same programs. (ABC, SBS, Nine)
NICAM stereo	A simple, clear stereo sound that comes from twin, built-in speakers. Providing you have the right connections you can always upgrade to a separate sound system.
NTSC (National Television System Committee)	The North American 525-line analog broadcast TV standard.
OLED (Organic Light Emitting Diode)	OLED is a display technology that can be used to create flat-panel TV TVs. An OLED panel employs a series of organic thin films placed between two transparent electrodes. An electric current causes these films to produce a bright light. A thin-film transistor layer contains the circuitry to turn each individual pixel on and off to form an image. The organic process is called electrophosphorescence, which means the display is self-illuminating, requiring no backlight. OLED panels are thinner and lighter than current plasma or LCD HDTVs, and have lower power consumption. Only small OLED screens are available at this time.
Optical Cable	A lot of TVs let you send surround sound from HDTV broadcasts back to your receiver via an optical digital audio cable.
Overscan	The portion of a video image that lies outside a TV's visible screen area. The amount of overscan varies from model to model, but typically ranges between 5% and 10% or the total image. Some recent TVs with "pixel-by-pixel" or "dot-by-dot" display modes are capable of showing the full image, with no overscan. This is especially advantageous when viewing 1080i or 1080p content on a 1080p TV.
Over-the-Air	Over-the-Air (OTA) refers to the transmission and reception of information in a wireless communication system.
PAL (Phase Alternative Line)	The television system used in Australia (and most European countries)
Pan-and-scan	The process of transferring a widescreen movie or other source material to videocassette, DVD, or broadcast so that it fits the squarish 4:3 aspect ratio of most old-fashioned TVs. This results in a significant amount of lost picture information, particularly in the width of the image. Most new HDTVs use the wider 16:9 aspect ratio, which can display all or most of the original picture of widescreen material.
Parental lock/Child lock	Parents may lock out unsuitable content for children.
Picture in Picture (PiP)	On screen features that allow programmes to be viewed simultaneously (One full screen, the other in a smaller window).
Pillar-boxed	The pillar-box effect occurs in widescreen 16:9 video displays when vertical black bars are placed at the sides of a non-widescreen 4:3 image. The smaller the size of the pixels in an image, the greater the resolution. To learn more about aspect ratios and ways to deal with black bars, see our aspect ratio article.
Pixel	Pixel is actually two words combined - "Picture" and "Element." Pixels are tiny samples of video information, the "little squares" that "add up" to an entire picture. A pixel is the smallest area of a television picture capable of being sampled and transmitted through a system, and displayed on a monitor. The greater the number of pixels, the better the resolution.
Pixel response time	The amount of time it takes for a single pixel in a video display to switch from active to non-active; it is measured in milliseconds (ms). If a display's response time is too slow, faint motion trails may be visible following fast-moving on-screen objects. Pixel response time is an important performance spec for all types of digital flat-panel and projection displays although it's rarely listed for non-LCD TVs. For smooth, accurate playback of high-quality video material, look for a response time of 8 ms or less.
Plasma	Plasma technology is one of the methods used to create flat-panel TVs. The display consists of two transparent glass panels with a thin layer of pixels sandwiched in between (somewhere between 800,000 and two million). Each pixel is composed of three gas-filled cells or sub-pixels (one each for the red, green and blue primary colours). A grid of tiny electrodes applies an electric current to the individual cells, causing the gas to ionize. This ionized gas (plasma) emits high-frequency UV rays which stimulate the cells' phosphors, causing them to glow, which creates the TV image. For more info on how plasma technology works, see our LCD vs. Plasma article. You can also check out our video comparing LCD and plasma TVs.
Postage Stamp	Some TV programs are letterboxed or pillar-boxed during broadcast, which results in a 16:9 format broadcast that already has bars above and below it. When such a broadcast is viewed on a 16:9 set, it results in bars appearing above, below, and on the sides - a result called a Postage Stamp.
Power output	The amount of energy produced by a component.
Progressive Scan	A way to scan vertical lines onto a TV picture by scanning all the lines consecutively (progressively). At the same number of lines, progressive scan produces a higher quality picture than interlace scan. All flat panel and many digital projection televisions are progressive scan, so they display progressive scan images more clearly compared to interlaced images.
Projector	A video display device that projects a large image onto a physically separate screen. The projector is typically placed on a table, or ceiling-mounted. Projectors, sometimes referred to as front-projection systems, can display images up to 10 feet across, or larger. Old-fashioned large, expensive CRT-based projectors have been replaced by compact, lightweight, lower-cost digital projectors using DLP, LCD or LCoS technology.
Pulldown, 3-2	A process by which a movie shot in 24 frames per second (fps) is shown as an interlace scan television image at 30 frames per second.
QAM (Quadrature Amplitude Modulation)	A digital modulation format used for downstream transmission in cable TV systems — commonly used for cable HDTV such as Foxtel.
Rabbit Ears	A term that describes a V-shaped set-top antenna that is adjustable in length and angle.
Rainbow effect	A visual artifact associated with single-chip DLP-based rear- and front-projection displays. Fortunately, only a few people see these momentary flashes of colour, and fewer still find these "rainbows" to be distracting. For those unlucky few, rainbows typically occur when the viewer's eyes dart away from the screen. Rainbows result from DLP's use of a colour wheel, which causes the three primary colours — red, green, and blue — to be projected sequentially, rather than continuously. Some recent single-chip DLP TVs have replaced the lamp-and-colour-wheel system with coloured LEDs, which reduce this effect. And rainbows aren't an issue for 3-chip DLP projectors because each primary colour has its own dedicated image chip, so no colour wheel is needed.
RCA Connectors	See Composite Video.
Rear Projection TV Set	This is typically a much larger set than a standard CRT TV set. This set creates an image on a small display and then enlarges it onto the back of the screen usually using a mirror. Old rear projection sets used a small CRT, while new digital projection sets use LCD, DLP (Digital Light Processing), or LCoS (Liquid Crystal on Silicon) to create brilliant, wide-angle pictures.
Resolution	A measure used to describe the quality of images a screen can display; refers to the number of pixels in the entire screen; for example, a resolution of 1280x1024 means that 1024 lines are drawn from the top to the bottom of the screen and each of these lines is made up of 1280 separate pixels. 480i (480 interlaced)
Response Time	A screen's signal reaction speed; quicker response times translate to smoother and more fluid images; articulated in terms of milliseconds (ms), such as 8ms.
RF (radio frequency) jack	Sometimes referred to as a "75-ohm coaxial" connection, this kind of jack is commonly used for bringing signals from antennas and other sources outside the home to components with some type of tuner, such as cable boxes, HDTV tuners, VCRs, satellite receivers, TVs, etc. A 75-ohm coaxial cable can carry video and stereo audio information simultaneously. However, as a way of making a video connection between components, RF is inferior to composite, S-video, component video, and HDMI. RF cable connectors (often called "F-type" connectors) either screw onto the 75-ohm jack, or just push on to connect. See our connections glossary for more info.
RF Jack (Radio Frequency Jack)	Carries video and stereo audio simultaneously from a broadcast, cable or satellite source to a device with a tuner; provides the lowest video quality of any connection.
RMS (Root Mean Square)	Often used to measure the power output of a device. Will provide a realistic measure of the output rather than the peak.
Rooftop Antenna	An antenna mounted on the roof of a structure.
Scaler	Circuitry that converts a video signal to a resolution other than its original format. Scaling can involve upconversion or downconversion, and may also include a conversion between interlaced- and progressive-scan formats. A scaler can be built into a TV, HDTV tuner, DVD player, or home theater receiver, or may be a standalone component.
Scanning lines	On CRT-based TVs, the number of scanning lines measures the screen's resolution. Scanning refers to an electron gun tracing horizontal lines across a phosphor-coated screen, painting each video frame as a series of lines. Although you may still hear the term "scan lines" used when describing digital TVs that use plasma, LCD, or other pixel-based technologies, it's not really accurate. These newer TV types flash each complete screen image simultaneously without any type of actual scanning.
SCART (Syndicat francais des Constructeurs d'Appareils)	A connector that transfers pictures and sound to the TV.
SDTV (Standard-Definition Television)	SDTV refers to the non-high-definition formats of the digital television standard. SDTV pictures can have either 4:3 or 16:9 aspect ratio. Picture and sound is clearer than analog PAL video, with picture resolution of 480i or 480p. These digital signals require less bandwidth than analog signals, allowing TV stations to simultaneously broadcast multiple channels of programming in place of a single analog channel; this is called "multicasting."
SECAM	The television system used in some European countries (PAL is used in Australia).
Set-Top Box	A stand-alone device that receives and decodes programming so that it may be displayed on a television. Set-top boxes may be used to receive broadcast, cable, and satellite programming.
Signal Booster	A device that receives an incoming broadcast signal, amplifies it, and retransmits it on the same frequency. Such devices are used to improve communications in locations within the normal coverage area of a broadcast system where the signal is blocked or shielded due to natural terrain or man-made obstacles.
Sleep timer	Will allow a TV to turn itself off after a set amount of time.
Spectrum	A range of electromagnetic radio frequencies used in the transmission of radio, data, and video.
SRS TruSurround sound	The effect of Dolby Surround Sound using only the two front speakers.
Subwoofer	A speaker that reproduces very low frequencies.
SVGA	Super Video Graphics Array. This is a display mode with a resolution of 800 x 600 pixels.
S-video	A high quality video connection cable. A 4-pin connector usually provides a good picture by transmitting the chrominance and luminance portions of a video signal separately. The signals can then be processed separately, reducing interference. Direct S-video connections generally outperform composite connections when hooking up video components that don't have component video or HDMI, like an old DVD player. However, they don't look as sharp as HD-capable connections like component video, and HDMI. See our connections glossary or our article about connecting your HDTV for more info.
SXRD™ — Silicon X-tal (Crystal) Reflective Display	Sony's variation of LCoS projection display technology.
Terrestrial Broadcasting	A broadcast signal transmitted over-the-air to an antenna.
Twin Lead	A term that refers to a two-conductor ribbon cable commonly used as the cable between an antenna and the TV for "older' TV antenna systems
Twin Lead Adapter	A device for connecting a Twin Lead cable to a coaxial cable.
UHF	Ultra High Frequency. This is the part of the radio spectrum from 300 to 3000 megahertz, which included TV channels 14-69. Post-DTV transition, UHF TV changed to 470 to 698 MHz, which includes channels 14-51.
Upconversion	The term used to describe the conversion of a lower resolution to an apparently higher one. This process increases the number of pixels and/or frame rate and/or scanning format used to represent an image by interpolating existing pixels to create new ones at closer spacing.
Upconvert	In DTV, the conversion from a lower-resolution input signal number to a higher one.
Upconvert	A process by which a digital, high-definition television takes a lower-definition picture and converts it into a higher-definition picture. This may be done by doubling each line as it is drawn on the screen, or by using advanced algorithms to interpolate the data between each lower-resolution line, filling in the missing image.
V-Chip	Several years ago the FCC (Federal Communications Commission) began requiring that TVs include "V-Chip" technology to block the display of television programs based on their rating. All sets with screens 13 inches or larger manufactured after January 1, 2000 must include the V-Chip. Broadcasters are required to encode an electronic signal in TV programs indicating the level of violence, language, and sexual content. Parents can program the TV with a rating so that when the the V-Chip reads a show's signal, it will prevent it from displaying if it is above the rating.
V-Chip	The V-chip is a technology that enables parents to block television programming based on a program's rating. The ratings are encoded within the television signal. The V-chip reads the encoded rating information of each program and blocks shows according to the parents' blocking selections.
VCR	Video Cassette Recorder.
Vertical Resolution	Number of horizontal lines or pixels that can be resolved from the top of an image to the bottom; the analog NTSC TV standard is 480 lines; digital TV signals have vertical resolution that ranges from 480 lines for standard-definition TV, to 720 or 1080 lines for high-definition TV.
VGA	Video Graphics Array. This is a display mode with a resolution of 640 x 480 pixels.
VHF	Very High Frequency. This is the part of the radio spectrum from 30 to 300 megahertz, which includes TV Channels 2-13, and the FM broadcast band.
Viewing angle	Measures a video display's maximum usable viewing range from the center of the screen, with 180° being the theoretical maximum. Most often, the horizontal (side to side) viewing angle is listed, but sometimes both horizontal and vertical viewing angles are provided. For most home theater setups, horizontal viewing angle is more critical.
Viewing Angles	Refers to the angle from which you can still view the picture on the screen; TVs with wide viewing angles don't require you to be positioned directly in front of the set to view an ideal picture; usually referred to in degrees, for example 178 Degrees.
Virtual Channel	In telecommunications, a channel designation which differs from the actual channel or frequency on which the signal travels. The term is most often applied to television, where Digital Television (DTV) channels are in-band adjacent to analog ones.
Virtual Dolby	A clever system that distributes the sound around the room from the twin, built-in speakers. This gives an effect similar to surround sound.
Visible screen size	The diagonal measurement in cm from one corner of the screen to the other.
Widescreen	When used to describe a TV, widescreen generally refers to an aspect ratio of 16:9, which is the optimum ratio for viewing anamorphic DVDs and HDTV broadcasts.
Widescreen	A term used generally to describe an aspect ratio wider than 4:3. For television, this refers to the 16 x 9 aspect ratio.
Wi-Fi	A short-range wireless technology that allows devices to connect to and transfer information over a local area network. A few Internet-ready TVs include Wi-Fi capability built-in, and most can connect wirelessly using an optional adapter.
Yagi Antenna	A type of directional antenna system, generally designed for UHF frequencies, which is ideal for receiving most DTV stations. Ranging in size from several inches to many feet, a Yagi Antenna is the most common design for rooftop antennas.