How Computer Monitors Work and How They've Changed

Monitors (or displays) are defined by color capability, resolution, size, refresh rate, and panel technology. CRTs are now obsolete for most users; mainstream options include LED-backlit LCDs (TN/IPS/VA), Mini-LED, and OLED. Choose a monitor based on the task: gaming favors high refresh and low response times, while content creation requires accurate color and higher resolutions.

Monitor vs. display

People often use "monitor" and "display" interchangeably. Traditionally, "monitor" referred to the entire enclosure (the box and electronics) while "display" referred specifically to the screen. Today the distinction matters less, but "monitor" still implies a complete device with inputs, controls, and stand.

Color, resolution, and size

Displays fall into color classes: monochrome (two colors), grayscale (multiple shades of gray), and color. Modern color displays reproduce millions of colors and support 8-bit (24-bit color) or higher color depth; some professional and HDR displays support 10-bit color or beyond.

Screen size is measured diagonally in inches. Common desktop sizes range from 21-27 inches for general use, 27-34 inches for content creation or gaming, and ultrawide formats (21:9 and wider) for multitasking. Aspect ratios are most commonly 16:9, though 16:10 and ultrawide ratios are popular for productivity.

Resolution describes the pixel grid: legacy standards included 1024×768 (SVGA) and 1280×1024 (SXGA). Modern standards include Full HD (1920×1080), QHD (2560×1440), and 4K/UHD (3840×2160). Pixel density is often expressed as pixels per inch (PPI).

Refresh rate, response time, and image quality

Refresh rate measures how often the image updates per second (Hz). Office displays commonly run at 60-75 Hz; gaming monitors often support 120, 144, 240, or even 360 Hz. Response time (measured in milliseconds) indicates how quickly pixels change state and affects motion clarity.

Interlaced scanning is now rare; most computer displays use progressive scan. Modern displays also advertise HDR capability, wider color gamuts (sRGB, Adobe RGB, DCI-P3), and hardware calibration options for accurate color.

Panel technologies

CRT (cathode-ray tube) monitors were once dominant but are now effectively obsolete for general computing due to their bulk and power use. Contemporary panel technologies include:

• LCD (liquid crystal display) with LED backlighting - the mainstream option. Manufacturers use variants such as TN (fast response, narrower viewing angles), IPS (better color and viewing angles), and VA (higher contrast).

• LED backlights have evolved into local-dimming and Mini-LED implementations for better contrast.

• OLED offers per-pixel light control, wide viewing angles, and deep blacks; it appears increasingly in high-end monitors and laptops.

Connectivity and other features

Most modern monitors accept HDMI and DisplayPort. USB-C with DisplayPort Alt Mode and power delivery is common on mobile-friendly monitors. Features to consider include built-in USB hubs, KVM switches, adjustable stands, VESA mount compatibility, and factory calibration for color-critical work.

Choosing a monitor

Match resolution and size to viewing distance and tasks. Gamers prioritize refresh rate and low response time. Photographers and designers prioritize color accuracy, panel uniformity, and calibration support. For general office use, a 24-27" 1080p-1440p IPS display at 60-75 Hz is usually a solid choice.