# Glossary of display terms

> The vocabulary of specification sheets, defined briefly and without jargon. Each entry points to the chapter of the handbook that treats it in depth.

Source: https://monitorselector.com/en/glossary/ (Monitor Selector, 2026-11-14)

**Adaptive-Sync**: The VESA standard for variable refresh rate over DisplayPort. FreeSync and G-Sync Compatible are built on it. See [refresh rate](https://monitorselector.com/en/refresh-rate-response-time/).

**Arcminute**: One sixtieth of a degree. An eye with 20/20 vision separates two details one arcminute apart, which sets the threshold of 60 pixels per degree. See [pixel density](https://monitorselector.com/en/pixel-density-ppi/).

**Aspect ratio**: The ratio of the width of the image to its height: 16:9 for standard monitors, 21:9 for ultrawide, 32:9 for super ultrawide, 16:10 for some office screens.

**Backlight**: The light source behind an LCD panel. It shines permanently; the liquid crystals in front of it block more or less of its light.

**Banding**: Visible steps in a gradient that should be smooth, caused by too few levels per colour. A 10-bit signal reduces it. See [colour](https://monitorselector.com/en/color-gamut-hdr/).

**Bit depth**: The number of bits used for each primary colour: 8 bits give 256 levels and 16.7 million colours, 10 bits give 1024 levels and 1.07 billion colours.

**Blooming**: A halo around a bright object on a dark background, on screens with local dimming, because the lit zone is larger than the object.

**Burn-in**: A permanent ghost image left on an OLED panel by an element displayed in the same place for thousands of hours. See [panel types](https://monitorselector.com/en/ips-va-oled-panel-types/).

**Colour space**: A standard set of colours defined by three primaries and a white point: sRGB, DCI-P3, Adobe RGB, Rec. 2020. An image is encoded for one colour space.

**Contrast ratio**: The brightness of white divided by that of black on the same screen. About 1000:1 for IPS, 3000:1 to 5000:1 for VA, unlimited for OLED.

**Curvature (R)**: The radius, in millimetres, of the circle a curved screen follows. 1800R is a gentle curve, 1000R a tight one.

**DCI-P3**: A colour space from digital cinema, about a quarter larger than sRGB, used for HDR video and by recent phones under the name Display P3.

**Delta E (ΔE)**: The measured difference between the colour requested and the colour displayed. Under 1 it is imperceptible, under 2 it is very good.

**DisplayHDR**: The VESA certification for HDR monitors. The number is the peak brightness in nits: 400, 600, 1000, 1400; “True Black” levels apply to OLED.

**DisplayPort**: The video link of computers. Version 1.4 carries 25.9 Gbit/s of image data, version 2.1 up to 77.4 Gbit/s. See [connections](https://monitorselector.com/en/hdmi-displayport-usb-c/).

**DisplayPort Alt Mode**: The mode in which a USB-C port carries a DisplayPort signal on its high-speed wires. It is what makes a USB-C port a video output.

**DSC**: Display Stream Compression: a visually lossless compression of the video signal, by a factor of up to three, used for high resolutions at high refresh rates.

**Flicker-free**: Said of a monitor whose backlight is dimmed by lowering the current, not by switching it on and off. See [eye comfort](https://monitorselector.com/en/eye-strain-flicker-blue-light/).

**FRC**: Frame rate control: rapid alternation between two neighbouring levels to simulate an intermediate one. “8 bit + FRC” approximates a 10-bit panel.

**Frame time**: The duration each image stays on screen: 1000 divided by the refresh rate. 16.7 ms at 60 Hz, 6.9 ms at 144 Hz.

**FreeSync**: AMD’s name for variable refresh rate. Its levels (FreeSync, Premium, Premium Pro) add requirements on the range and on HDR.

**Gamut**: The range of colours a screen can display, the triangle formed by its three primaries. Expressed as coverage of a colour space, for example 95% DCI-P3.

**G-Sync**: Nvidia’s name for variable refresh rate. “G-Sync Compatible” monitors use the Adaptive-Sync standard and are validated by Nvidia.

**GtG**: Grey to grey: the usual measure of response time, the duration a pixel takes to pass from one shade of grey to another.

**HDMI**: The video link of televisions and consoles, also present on monitors. Version 2.0 carries 4K at 60 Hz; version 2.1, up to 4K at 144 Hz and beyond.

**HDR**: High dynamic range: images encoding highlights far brighter than ordinary white and details in deep shadows. Requires a very bright screen with local dimming, or OLED.

**Input lag**: The delay between the arrival of a signal at the monitor and the display of the image. Under 5 ms on good monitors; far more on televisions outside game mode.

**IPS**: In-plane switching: the LCD technology with the most stable colours and the widest viewing angles. Contrast about 1000:1, twice that for IPS Black.

**KVM**: A switch built into some monitors that moves keyboard, mouse and other USB peripherals from one computer to another along with the video input.

**Local dimming**: Division of an LCD backlight into zones that are dimmed independently behind dark areas of the image, to deepen blacks.

**Mini-LED**: A backlight made of thousands of small diodes in hundreds or thousands of zones. It gives an LCD high brightness and effective local dimming.

**MST**: Multi-Stream Transport: DisplayPort’s ability to feed several monitors from one output, by chaining them or through a hub. Not supported by macOS for extending the desktop.

**Nit**: The unit of screen brightness, equal to one candela per square metre (cd/m²). An office screen is used at 100 to 150 nits; HDR highlights reach 1000 and more.

**OLED**: Organic light-emitting diode: each pixel emits its own light and can switch off completely, giving perfect blacks and near-instant response.

**Overdrive**: Acceleration of pixel transitions by briefly over-driving them. Set too high, it produces bright trails behind moving objects (overshoot).

**Pixel pitch**: The distance between the centres of two neighbouring pixels, in millimetres: 25.4 divided by the PPI.

**Power Delivery**: The USB standard by which a monitor charges a laptop through the USB-C video cable. Monitors supply 65 to 140 W.

**PPD**: Pixels per degree: the number of pixels inside one degree of the field of view at a given distance. The measure of perceived sharpness; 60 PPD matches 20/20 vision. Try the [calculator](https://monitorselector.com/en/ppi-calculator/).

**PPI**: Pixels per inch: the density of a panel, computed from its resolution and diagonal. 109 PPI for a 27-inch 1440p screen, 163 PPI for a 27-inch 4K screen.

**PWM**: Pulse-width modulation: dimming a light by switching it on and off rapidly. At low frequency it can cause visible flicker and discomfort.

**QD-OLED**: An OLED panel whose blue light is converted into red and green by quantum dots. Very pure colours; triangular sub-pixel layout.

**Refresh rate**: The number of images the monitor displays per second, in hertz. 60 Hz is the base, 144 Hz the base for games.

**Response time**: The duration a pixel takes to change shade. It must stay under the frame time for motion to be clean.

**Scaling**: The operating-system setting that enlarges the interface on dense screens: 125%, 150%, 200%. It trades workspace for sharpness. See [resolution and scaling](https://monitorselector.com/en/resolution-and-scaling/).

**sRGB**: The standard colour space of the web, office software and most games. An image without a colour profile is assumed to be sRGB.

**Sub-pixel**: One of the red, green or blue elements that make up a pixel. Their arrangement (stripe, triangle) affects how text is rendered.

**Thunderbolt**: A link using the USB-C connector with a guaranteed 40 Gbit/s (80 for Thunderbolt 5), carrying video, data and power on one cable.

**TN**: Twisted nematic: the oldest LCD technology, fast and cheap, with poor colours and narrow viewing angles.

**Uniformity**: The consistency of brightness and colour over the surface of the screen. Monitors for image work compensate for it electronically.

**VA**: Vertical alignment: the LCD technology with the highest native contrast, 3000:1 to 5000:1, and slower dark transitions.

**VESA mount**: The standard pattern of four threaded holes on the back of a monitor, usually 100 × 100 mm, for arms and wall mounts.

**Viewing angle**: On this site: the horizontal angle the screen fills in the field of view, from the seat. On specification sheets: the angle from which the image remains acceptable.

**VRR**: Variable refresh rate: the monitor displays each image when the graphics card delivers it, which removes tearing and stutter.

**White point**: The colour of white on a screen, given as a colour temperature. The standard is D65, a daylight white of about 6500 K.