4K (UHD)
A resolution of 3840 x 2160 pixels—four times the pixel count of 1080p Full HD. Now the baseline for mid-range and premium TVs, 4K delivers noticeably sharper detail at typical living-room sizes and viewing distances.
TV glossary
HDR, VRR, eARC, local dimming: the words on the box and in your TV’s settings menu, explained in a sentence or two each.
51 terms, A to Z
51 terms
Numbers
8K
A resolution of 7680 x 4320 pixels, four times that of 4K. Native 8K content is still scarce, so most of the benefit today comes from upscaling—the higher pixel density mainly pays off on very large screens viewed up close.
Letter A
ABL (Automatic Brightness Limiter)
A protective circuit, most common on OLED panels, that lowers overall brightness when a large portion of the screen is bright. It prevents excessive power draw and heat, but can cause full-screen white scenes to dim—a trade-off for panel longevity.
ALLM (Auto Low Latency Mode)
An HDMI feature that lets a console or PC tell the TV to switch automatically into its low-latency Game mode when a game launches, and back out for video. Removes the need to change picture modes by hand.
Aspect Ratio
The proportional relationship between a screen's width and height. Modern TVs are 16:9 (widescreen); many films are shot wider (such as 2.39:1), which is why letterbox bars appear above and below the image.
Letter B
Backlight
The light source behind an LCD panel that makes the image visible. Because the liquid-crystal layer only blocks or passes light, backlight design—edge-lit, full-array, or Mini-LED—largely determines an LCD TV's brightness and black-level performance.
Banding
Visible stepped bands in what should be a smooth gradient, such as a sunset sky. Caused by insufficient bit depth or aggressive compression; higher bit depth and better source encoding reduce it.
Bit Depth
The number of bits used to describe each color channel of a pixel. 8-bit yields about 16.7 million colors; 10-bit yields over a billion and is required for smooth HDR gradients without visible banding.
Black Level
How dark a display can render black. Deeper black levels increase perceived contrast and detail in shadowy scenes. OLED achieves perfect blacks by switching pixels fully off; LCDs rely on local dimming to approximate it.
Bloom (Blooming)
A halo of stray light around bright objects on a dark background, seen on LED LCDs with local dimming. It happens because each dimming zone covers many pixels, so light spills from bright zones into adjacent dark ones.
Burn-in
Permanent retention of a static image—such as a channel logo or game HUD—caused by uneven pixel wear, primarily a risk on OLED panels. Modern OLEDs include pixel-shifting and refresh routines that make it unlikely with normal, varied viewing.
Letter C
Color Gamut
The full range of colors a display can reproduce, typically measured against standards like Rec.709 (HD), DCI-P3 (digital cinema), or Rec.2020 (UHD). A wider gamut means more saturated, lifelike reds, greens, and blues.
Contrast Ratio
The difference between the brightest white and the darkest black a screen can show at once. Higher contrast produces more depth and punch. Be wary of inflated 'dynamic' contrast figures in marketing—native contrast is what you actually see.
Letter D
Dolby Atmos
An object-based surround-sound format that adds a height dimension, letting effects move around and above the listener. On TVs it can be delivered to a compatible soundbar or receiver, usually over eARC.
Dolby Vision
A premium HDR format that uses dynamic metadata to adjust brightness and color scene by scene (or frame by frame), optimizing the picture for each display. Requires both content and TV support.
Letter E
eARC (Enhanced Audio Return Channel)
An HDMI 2.1 feature that sends high-bandwidth, lossless audio—including Dolby Atmos and DTS:X—from the TV back to a soundbar or receiver over a single HDMI cable. The successor to the older, bandwidth-limited ARC.
Letter F
FALD (Full-Array Local Dimming)
A backlight in which LEDs sit behind the entire panel and are grouped into independently controlled zones. More zones mean tighter control over brightness and black levels, with less blooming than edge-lit dimming.
Frame Rate
How many frames of video are shown per second (fps). Film is typically 24fps, broadcast TV 30 or 60fps, and modern games up to 120fps. The TV's refresh rate must keep pace to display high frame rates smoothly.
FreeSync
AMD's variable refresh rate technology that syncs the TV's refresh rate to a game's frame rate to eliminate screen tearing and stutter. Widely supported on Xbox consoles and AMD/Radeon PCs.
Letter G
G-Sync
NVIDIA's variable refresh rate technology for tear-free, low-stutter gaming. Some TVs are 'G-Sync Compatible', meaning they work with NVIDIA GPUs over standard VRR rather than requiring a dedicated G-Sync module.
Gamma
The curve that maps input signal levels to displayed brightness, controlling how mid-tones appear. A correct gamma (often 2.2 or 2.4 for SDR) keeps shadows and highlights looking natural rather than washed out or crushed.
Letter H
HDMI
High-Definition Multimedia Interface—the standard cable and connector that carries digital video and audio between devices and a TV. Different versions support different resolutions, frame rates, and features.
HDMI 2.1
The HDMI version that adds the bandwidth for 4K at 120Hz, 8K at 60Hz, and gaming features such as VRR, ALLM, and eARC. Look for full-bandwidth (48Gbps) ports if you plan to game at high frame rates on a current console or PC.
HDR (High Dynamic Range)
A set of technologies that expand the range between the darkest and brightest parts of an image and widen the color palette, for more lifelike highlights and richer color. HDR10, HDR10+, Dolby Vision, and HLG are the main formats.
HDR10
The baseline, royalty-free HDR format supported by virtually all HDR TVs and content. It uses static metadata, meaning one set of brightness instructions applies to the whole title rather than adapting scene by scene.
HDR10+
An open HDR format that adds dynamic, scene-by-scene metadata on top of HDR10—a royalty-free alternative to Dolby Vision. Backed primarily by Samsung and Amazon Prime Video.
HLG (Hybrid Log-Gamma)
An HDR format designed for live broadcast and streaming that carries both SDR and HDR information in a single signal, so it displays correctly on both HDR and non-HDR TVs without separate feeds.
Letter I
Input Lag
The delay between a signal reaching the TV and the corresponding image appearing on screen—critical for gaming responsiveness. Game mode minimizes it; under ~15ms is excellent, while a value over ~40ms feels sluggish.
IPS Panel
A type of LCD panel (In-Plane Switching) prized for wide viewing angles and color consistency off-axis, but with weaker native contrast and more backlight glow than VA panels. Common where many people watch from the sides.
Letter J
Judder
A subtle stutter in motion, most visible in slow camera pans of 24fps film when the frame rate doesn't divide evenly into the display's refresh rate. Motion-interpolation settings can reduce it, sometimes at the cost of the 'soap opera effect'.
Letter L
LED LCD
The most common TV type: a liquid-crystal display lit by LED backlighting. Picture quality depends heavily on the panel type (VA or IPS) and the sophistication of the backlight and local dimming.
Local Dimming
A backlight technique that dims or brightens regions of the screen independently to deepen blacks and lift contrast on LCD TVs. Effectiveness scales with the number of dimming zones and whether the backlight is edge-lit or full-array.
Letter M
Mini-LED
A backlight built from thousands of much smaller LEDs, enabling far more local-dimming zones than conventional LED backlights. The result is higher peak brightness and less blooming, narrowing the gap with OLED's black levels.
Motion Blur
Smearing of fast-moving objects, caused mainly by how long each frame is held on screen (pixel persistence) plus pixel response time. Higher refresh rates and black-frame insertion can sharpen motion.
Letter N
Nits (cd/m²)
The unit of luminance used to describe display brightness; one nit equals one candela per square meter. Typical SDR viewing sits around 100-200 nits, while strong HDR highlights can exceed 1,000 nits on capable TVs.
Letter O
OLED
Organic Light-Emitting Diode—a panel technology where each pixel makes its own light and can switch off completely, producing perfect blacks, infinite contrast, and excellent viewing angles. No backlight is needed.
Overscan
A legacy behavior where the TV slightly crops and zooms the image, cutting off the edges. It can hide content and soften detail; switching the picture-size setting to 'Just Scan', 'Full', or '1:1' restores the full frame.
Letter P
Peak Brightness
The maximum luminance a TV can output, usually for small bright highlights and measured in nits. High peak brightness makes HDR specular highlights—sun glints, explosions—pop and helps a screen fight glare in bright rooms.
Letter Q
QD-OLED
A hybrid panel that pairs an OLED light source with a quantum-dot color layer, combining OLED's perfect blacks with the brightness and color volume gains of quantum dots. Used in some premium TVs and monitors.
QLED
A marketing term for LED LCD TVs that use a quantum-dot layer to boost color brightness and saturation. Despite the name's similarity to OLED, QLED is still a backlit LCD—not a self-emissive panel.
Quantum Dots
Microscopic semiconductor particles that emit very pure colored light when energized. Adding a quantum-dot layer to an LCD or OLED widens the color gamut and improves color brightness.
Letter R
Refresh Rate
How many times per second the screen redraws its image, measured in hertz (Hz). 60Hz is standard; 120Hz panels handle high-frame-rate gaming and smoother motion. Ignore inflated 'effective' or 'motion rate' figures.
Resolution
The number of pixels that make up the image, written as width x height. More pixels (such as 4K's 3840 x 2160) allow finer detail, though the benefit depends on screen size and how close you sit.
Response Time
How quickly a pixel can change from one color to another, measured in milliseconds. Faster response times reduce motion blur and ghosting. OLED is near-instant; LCD response varies by panel type.
Letter S
Smart TV
A television with built-in internet connectivity and an app platform—such as Tizen, webOS, Google TV, Roku TV, or Fire TV—for streaming services, web features, and voice assistants without an external box.
Letter T
Tone Mapping
The process a TV uses to fit HDR content's brightness range into what the panel can actually display. Good tone mapping preserves highlight detail instead of clipping bright areas to flat white.
Letter U
Upscaling
The TV's processing that converts lower-resolution content—like HD or DVD—to fill its higher-resolution panel. Quality varies widely by brand; strong upscaling adds sharpness and reduces noise without introducing artifacts.
Letter V
VA Panel
A type of LCD panel (Vertical Alignment) that delivers high native contrast and deep blacks, making it strong for movies in darker rooms. The trade-off is narrower viewing angles, so the image washes out from the sides.
Variable Refresh Rate (VRR)
A feature that lets the TV's refresh rate adjust on the fly to match a game's fluctuating frame rate, eliminating screen tearing and stutter. Delivered via HDMI 2.1 VRR, AMD FreeSync, or NVIDIA G-Sync Compatible modes.
Viewing Angle
How far off-center you can sit before the picture loses contrast, color, or brightness. OLED and IPS panels hold up well from the sides; VA panels degrade more sharply—important for wide seating layouts.
Letter W
Wide Color Gamut (WCG)
A color range that extends well beyond the older Rec.709 HD standard, typically targeting DCI-P3 or Rec.2020. Paired with HDR and quantum dots, WCG produces more saturated, true-to-life colors.
See the terms in action
Our guides use these settings step by step, with the exact menus on Samsung, LG, Hisense and Insignia TVs.