Traditional TVs have an aspect ratio of 4:3 (squarish), which represents the ratio of the width of the screen to the height. Widescreen TVs have an aspect ratio of 16:9 (also known as "letterbox", a rectangular shape). If you plan to watch a lot of DVD movies on your TV, you might want to consider a widescreen TV, as many DVDs support the 16:9 aspect ratio. If you have a widescreen TV and are viewing standard programming, the picture will appear in letterbox format, meaning that the picture will appear with black boxes on either side or the top and bottom of the screen.
Contrast Ratio is the difference between the whitest white and the darkest black colors the display can show. The greater the contrast, the better the screen and the subtlety of colors it can display.
Digital TV Standard refers to the way in which your television receives and displays signals:
EDTV (Enhanced Definition Television) - The picture quality of EDTV is superior to that of standard analog TV (480i) but not as good as HDTV (1080i or 720p). EDTV displays the picture at a resolution of 852x480 (480p) lines in either 4:3 or 16:9 aspect ratios and it includes Dolby Digital sound system.
HDTV (High Definition Television) - An improved television system which provides twice the vertical and horizontal resolution of existing television standards. It also provides audio quality approaching that of compact discs. It capables of displaying on a wider screen (16x9 as opposed to the conventional 4x3) and at higher resolution.
SDTV (Standard Definition Television) - The SDTV picture, having either in 4:3 or 16:9 aspect ratios, is better and of higher quality than the one of NTSC, however, it does not reach the quality and resolution of HDTV.
Flat Panel TVs use LCD, Plasma, or today's new type of viewing screen LED.
LCDs (Liquid Crystal Displays) use liquid crystals as optical shutters, which control the amount of light passing through the thin display screen, creating vivid, life-like colors. LCDs are commonly used on microwaves, calculators and computers, as well as projection (up to 60") and direct view (10"-30") TVs.
Plasma displays use a complex gas-based system. The benefits are a vivid, bright, clear picture with a slim form factor that can be mounted on a wall or on a pedestal. Plasma TVs range from 42 inches to 63 inches.
OLED (Organic Light-Emitting Diode) can provide brighter, crisper displays on electronic devices and use less power than conventional light-emitting diodes (LEDs) or liquid crystal displays (LCDs) used today, it also can be viewed in bright lighting conditions, at greater angles.
The broadcast formats supported by your television dictate what sort of signals your television is able to receive and process. It is important that your television not only support but is also able to display the formats you wish to view. A supported format can be understood by your television, but not necessarily displayed in its optimum form. 1080i, 1080p and 720p are standards for HDTV, while 480p and 480i are standard definition formats.
The broadcast formats displayed by your television dictate what sort of signals your television is able to receive and display. The number represents how big the picture will be, and the letter represents the way in which the image is refreshed. Generally, the higher the number, the more clearly it will show up on bigger screens. While progressive (p) formats refresh images twice as often as interlaced (i) formats, most users would not notice a significant difference between the two. 1080i, 1080p and 720p are standards for HDTV, while 480p and 480i are standard definition formats.
There are various types of tuners that may be built into a television:
NTSC (National Television System Committee) is the analog television broadcasting standard used widely in North America. It is referred to as a 525-line standard, but actually displays only 480 lines. NTSC is to be replaced with new DTV (Digital TV) standards in the coming years.
\r\nThe PAL (Phase Alternating Line) standard was introduced in the early 1960's and was implemented widely in Europe. It has a wider channel bandwidth than NTSC as it runs on 635 lines.
\r\nATSC (Advanced Television Standards Committee) creates the technical standards for the US digital television system (DTV). These standards are expected to be used in most new televisions, as the US television system shifts from analog to digital.
\r\nQAM (Quadrature Amplitude Modulation) tuner is present in some new digital televisions and similar devices. It enables direct reception of digital cable channels without the use of a set-top box. QAM tuners can be likened to the cable equivalent of an ATSC tuner which is required to receive over-the-air (OTA) digital channels broadcast by local television stations.
Native Aspect Ratio refers to the dimensions of the display of a television. It measures the units wide, by the units high. The two standard measurements for flat panel televisions and various types of projectors are 4:3 and 16:9. 4:3 produces a traditional square display. 16:9 produces a rectangular, wide screen display. One ratio is not necessarily better than the other. It all depends on the preferences of the consumer.\r\n
Variable audio output connectors allow you to control the volume of your TV with your TV's remote control, even when it is connected an audio receiver. This is a useful feature if your remote control does not work with your receiver.
There are various types of audio capabilities that may come with your television:
Mono: Single-channel sound, usually using a single speaker.
Stereo: Dual-channel sound, usually using two speakers.
Surround: Multiple-channel sound, using multiple speakers (usually six) for greater audio depth. There are many types of surround sound, and audio systems vary in the number of speakers and technologies used to produce surround sound.
Virtual Surround: Simulated multiple-channel sound with fewer (two or three) speakers.
Parental control features allow parents to restrict children's access to television programming. The most common parental control is the V-Chip, which allows parents to use the TV rating system to block particular programs.
Picture in Picture (PIP) allows you to watch more than one channel at the same time. With PIP, one channel will be displayed on the entire TV screen, and another channel or channels will be displayed in smaller squares on the screen.
Remote controls come in several different types, but among the most common are the standard remote, which only works on your TV, and the universal remote, which allows you to control not only your TV, but other video and audio components.