Monitor

Photo: Quaritsch Photography on Unsplash

In short: An external output device that graphically displays a computer’s video signal — often used synonymously with “screen” in everyday language.

In more detail: Important specs are resolution (e.g. 1920×1080), refresh rate (Hz) and response time. A monitor is usually connected via HDMI or DisplayPort, older devices also via VGA.

In Depth

There’s a subtle terminological distinction between “monitor” and “screen” that often blurs in everyday use: a screen generally refers to any display surface, regardless of whether it’s built in (e.g. on laptops or smartphones) or standalone. A monitor is specifically a standalone, external display device connected to a separate computing unit via a cable — so every monitor has a screen, but not every screen is a monitor.

Response time (usually given in milliseconds, e.g. 1 ms) describes how quickly a single pixel can change colour — a response time that’s too slow leads to visible motion blur (“ghosting”) with fast-moving image content. Together with a high refresh rate (Hz), it’s especially relevant for fast-paced games. Technologies like Adaptive Sync (cross-vendor) or proprietary variants additionally dynamically adjust the monitor’s refresh rate to the frame rate actually delivered by the graphics card, to avoid image errors like tearing (a visible “break” in the image caused by unsynchronised frame changes).

Panel technologies

The panel technology used strongly affects image quality and use case: TN panels (Twisted Nematic) are the cheapest and offer the shortest response times, but weaker colours and viewing angles. IPS panels (In-Plane Switching) deliver considerably better colour accuracy and viewing-angle stability, historically with a somewhat slower response time (though the gap to TN has shrunk considerably in modern IPS panels). VA panels (Vertical Alignment) sit in between, with a particularly high contrast ratio (deeper blacks), but often visible “ghosting” with fast dark image content.

Colour space and calibration

For image editing or graphic design, besides resolution and refresh rate, the colour space covered (e.g. sRGB, Adobe RGB, DCI-P3) is relevant — a monitor that only covers a fraction of the sRGB colour space displays colours noticeably less accurately than the original image intends. Professional monitors are additionally calibrated at the factory or with external calibration devices, to ensure colour reproduction that’s as faithful to the original as possible.

See also: Screen, HDMI, DP (DisplayPort), VGA