What Is a Computer Monitor?
A computer monitor is an external display that shows the images, text, and video produced by a desktop PC, laptop, or other device. It connects through a cable such as HDMI, DisplayPort, or USB-C and turns the signal from the computer’s graphics processor into the picture you see on screen.
A monitor doesn’t process or store information on its own. Instead, it determines how sharp, smooth, colorful, and comfortable your on-screen experience is. This page explains how monitors work, the main types, the specs that matter most, and how to choose and set one up. Each topic links to a dedicated glossary page for more detail.
Monitor essentials at a glance
An output device that displays what your computer’s graphics processor sends to it
Connects to a computer with a video cable or, on some models, a single USB-C cable that can also carry data and power
Most monitors use LCD panels with LED backlighting, while OLED monitors light each pixel individually
Screen size, resolution, refresh rate, and panel type have the biggest effect on image quality and feel
Works with desktops as a primary screen and with laptops as a larger or second screen
How Does a Computer Monitor Work?
A computer monitor works by receiving a video signal from a computer and lighting up millions of tiny dots, called pixels, to recreate each frame. The graphics processor in your computer builds every frame, sends it through the video cable, and the monitor refreshes the screen many times per second to show motion.
Pixels and subpixels
Every image on a monitor is made of pixels arranged in a grid. Each pixel contains red, green, and blue subpixels that combine at different brightness levels to produce the full range of on-screen colors. The number of pixels in the grid is the monitor’s resolution.
LCD and OLED display technology
Most monitors use a liquid crystal display (LCD) panel. Liquid crystals control how much light from an LED backlight passes through each subpixel. The way the crystals are arranged defines the panel type, such as IPS, VA, or TN.
Organic light-emitting diode (OLED) monitors work differently. Each pixel produces its own light and can turn off completely, which creates deep blacks and high contrast. Compare monitor panel types.
Refreshing the image
A monitor redraws the full screen a set number of times per second, measured in hertz (Hz). A 60 Hz monitor refreshes 60 times per second, while a 144 Hz monitor refreshes 144 times per second for smoother motion. How quickly each pixel changes color is called response time. Learn how refresh rate and response time work together.
What Are the Different Types of Computer Monitors?
Computer monitors are usually grouped by how they’re used, such as everyday computing, business, gaming, creative work, or travel. Many monitors fit more than one category. For example, a curved ultrawide monitor can serve both gaming and productivity.
Monitor type | Built for | Typical features | Learn more |
|---|---|---|---|
Everyday monitors | Browsing, streaming, schoolwork, and home office tasks | Full HD resolution, 22- to 27-inch screens, HDMI input, built-in speakers on some models | |
Business monitors | Office productivity and shared workspaces | Adjustable stands, USB-C connectivity, eye comfort features, built-in webcams on conferencing models | |
Gaming monitors | Fast-paced games and smooth motion | High refresh rates such as 165 Hz or 240 Hz, fast response times, adaptive sync | |
Creative monitors | Photo editing, video, and design | 4K or higher resolution, wide color coverage, factory color calibration | |
Ultrawide and curved monitors | Multitasking, spreadsheets, timelines, and immersive gaming | 21:9 or wider aspect ratio, curved screens on many models | |
Portable monitors | A second screen for laptops on the go | Slim 14- to 16-inch designs, USB-C power and video over one cable |
We offer monitors across these categories, including HP Series 3 Pro, HP Series 5, HP Series 5 Pro, and HP Series 7 Pro monitors for home and work, and HP OMEN gaming monitors. Shop HP monitors.
Understanding Monitor Specifications
Monitor specifications describe how large, sharp, smooth, and colorful a screen is, and how it connects to your computer. These are the specs that make the biggest difference for most people.
Monitor screen size
Monitor size is measured diagonally from one corner of the viewable screen to the opposite corner. Common desktop sizes range from about 22 to 34 inches, with 24- and 27-inch monitors among the most popular for home and office use. The right size depends on your desk depth, viewing distance, and resolution. Learn how to choose a monitor size.
Monitor resolution
Resolution is the number of pixels a monitor displays, written as width × height. Higher resolution shows sharper text and images and fits more content on screen, especially on larger monitors.
Resolution name | Pixels (width × height) | Common monitor sizes |
|---|---|---|
Full HD (FHD, 1080p) | 1920 × 1080 | 21.5 to 27 inches |
WUXGA | 1920 × 1200 | 24 inches |
QHD (1440p) | 2560 × 1440 | 27 to 32 inches |
4K Ultra HD (UHD) | 3840 × 2160 | 27 to 32 inches and larger |
See how monitor resolution affects image quality.
Refresh rate and response time
Refresh rate is how many times per second a monitor updates the image, measured in Hz. Response time is how quickly a pixel changes from one color to another, usually measured in milliseconds (ms). A 60 Hz to 100 Hz monitor suits everyday work, while gamers often choose 144 Hz or higher. Compare refresh rate and response time.
Panel type
The panel type affects color, contrast, viewing angles, and speed. In-plane switching (IPS) panels are known for consistent color and wide viewing angles. Vertical alignment (VA) panels offer higher contrast. Twisted nematic (TN) panels prioritize speed. OLED panels deliver deep blacks and fast response times. Compare IPS, VA, TN, and OLED panels.
Color accuracy and HDR
Color performance is often described by color gamut, the percentage of a standard color space such as sRGB or DCI-P3 that a monitor can display. High dynamic range (HDR) expands the range between the brightest and darkest parts of an image when the content supports it. Learn how color gamut and HDR work.
Aspect ratio
Aspect ratio is the relationship between a screen’s width and height. Most monitors use 16:9, some productivity monitors use 16:10 for extra vertical space, and ultrawide monitors use 21:9 or wider. Learn about aspect ratios and ultrawide monitors.
Ports and connectivity
Monitor ports determine which computers you can connect and how many cables you need. Common inputs include HDMI, DisplayPort, and USB-C. Some USB-C and Thunderbolt™ monitors can carry video, data, and laptop charging over a single cable, and some support daisy chaining a second monitor. Compare monitor ports and connections.
Monitor vs. TV vs. Laptop Screen vs. All-in-One
A monitor, TV, laptop screen, and all-in-one display can look similar, but they’re designed for different viewing distances, inputs, and uses. The biggest difference is that a monitor is a standalone screen built for close-up computer work, while a laptop screen and an all-in-one display are built into the computer itself.
Feature | Computer monitor | TV | Laptop screen | All-in-one computer |
|---|---|---|---|---|
What it is | External display for a computer | Display built for video content from many sources | Display built into a laptop | Computer with the components built into the display |
Typical viewing distance | About 20 to 30 inches | Several feet | About 15 to 25 inches | About 20 to 30 inches |
Typical size | 22 to 34 inches, ultrawides up to 49 inches | 32 inches and larger | 13 to 18 inches | 22 to 34 inches |
Common inputs | HDMI, DisplayPort, USB-C | HDMI, antenna or cable, built-in streaming apps | None; it’s the laptop’s own screen | Usually none, though some models support external video input |
Strengths | Sharp text up close, adjustable stands, high refresh rates | Large screen, built-in tuner and smart apps | Portability | Fewer cables and a compact footprint |
Upgrade flexibility | Can be replaced or added without changing the computer | Separate from the computer | Replaced only with the laptop | Display and computer are replaced together |
A TV can work as a computer screen, but it’s usually larger than needed at desk distance and may add input lag. For laptop users, an external monitor adds screen space while keeping the laptop portable. Learn more about laptops, desktop computers, and all-in-one computers.
How to Choose a Computer Monitor
The best way to choose a computer monitor is to start with how you’ll use it, then match the size, resolution, refresh rate, and ports to that use and to your computer. A monitor for spreadsheets and video calls needs different specs than one for competitive gaming or photo editing.
Monitor specs by use
These are general starting points. The right configuration also depends on your budget, desk space, and what your computer’s graphics can support.
Use | Screen size | Resolution | Refresh rate | Also look for |
|---|---|---|---|---|
Everyday and home use | 24 to 27 inches | Full HD | 60 to 100 Hz | Eye comfort features, built-in speakers |
Office productivity | 24 to 27 inches, or 34-inch ultrawide | Full HD to QHD | 60 to 100 Hz | Height-adjustable stand, USB-C, 16:10 option |
Gaming | 24 to 32 inches | Full HD to QHD | 144 Hz or higher | Fast response time, adaptive sync |
Creative work | 27 to 32 inches | QHD to 4K | 60 Hz or higher | Wide color gamut, factory color calibration |
Laptop on the go | 14 to 16 inches | Full HD or higher | 60 Hz | Single-cable USB-C power and video |
Check compatibility with your computer
Before you buy, confirm that your computer has a port the monitor accepts, such as HDMI, DisplayPort, or a USB-C port that supports video output. Not every USB-C port carries video, so check your laptop’s specifications. Your graphics processor also needs to support the monitor’s resolution and refresh rate to get the full benefit.
Think about comfort and space
Measure your desk and plan for a viewing distance of roughly an arm’s length. Stands that adjust for height, tilt, and swivel make it easier to position the screen at a comfortable eye level. Explore monitor ergonomics and eye comfort.
For more detail by use case, see our guide to choosing a monitor for work, gaming, or creative projects.
Setting Up and Using a Computer Monitor
Setting up a computer monitor usually takes a few minutes: connect the cable, turn on the monitor, and adjust your display settings. Getting the position and settings right makes everyday use more comfortable.
How to connect a monitor to a computer
Check which video ports your computer and monitor share, such as HDMI, DisplayPort, or USB-C.
Connect the monitor with a matching cable, or use an adapter if the ports differ.
Plug in the monitor’s power, unless it’s powered over USB-C, and turn it on.
In Windows, open Settings > System > Display to set the resolution, refresh rate, scaling, and screen arrangement.
Use the monitor’s on-screen menu to adjust brightness, contrast, and color modes.
Need a different connector? Learn about display cables and adapters.
Using multiple monitors
Many computers can run two or more monitors at once, which gives you more space to multitask. You can extend your desktop across screens or duplicate the same image on each. The number of monitors you can connect depends on your computer’s ports and graphics. Learn how to set up a multi-monitor workspace.
Connecting a monitor to a laptop
An external monitor turns a laptop into a larger workstation at your desk. A USB-C monitor or a docking station can connect the screen, keyboard, mouse, and charging through one cable, so you can plug in and unplug quickly.
Positioning for comfort
Place the top of the screen at or slightly below eye level, about an arm’s length away. Reduce glare by angling the monitor away from windows, and take regular breaks from the screen. Many monitors include low blue light modes or flicker-free backlights. Learn more about monitor ergonomics and eye comfort.
Monitor Glossary Topics A to Z
Aspect ratio and ultrawide monitors: How 16:9, 16:10, and 21:9 screens differ, and when an ultrawide makes sense.
Color and HDR: What color gamut, color accuracy, and high dynamic range mean for your screen.
Ergonomics and eye comfort: How to position a monitor and which features support comfortable viewing.
Monitor connectivity: How HDMI, DisplayPort, USB-C, and Thunderbolt connections compare.
Monitor size: How monitor size is measured and how to pick the right size for your desk.
Monitors by use: Which monitor features matter for work, gaming, creative projects, and home use.
Multi-monitor setups: How to connect and arrange two or more monitors.
Panel types: How IPS, VA, TN, and OLED panels differ in color, contrast, and speed.
Portable monitors: How lightweight USB-C monitors add a second screen to a laptop on the go.
Refresh rate and response time: What Hz and milliseconds mean and how they affect motion.
Resolution: How Full HD, QHD, and 4K compare and what pixel density means.
For gaming-specific display features such as adaptive sync and high refresh rates, see the gaming display features glossary.
Frequently Asked Questions About Computer Monitors
Is a computer monitor an input or output device?
A computer monitor is an output device because it displays information sent from the computer. A touch screen monitor is an exception: it also works as an input device, since it sends touch commands back to the computer.
What is the difference between a monitor and a display?
A display is any screen that shows visual information, including the built-in screens on laptops, tablets, and phones. A monitor is a standalone display that connects to a computer with a cable. In everyday use, the terms are often used interchangeably.
Does a desktop computer need a monitor?
A tower desktop or mini PC needs a separate monitor because it doesn’t have a built-in screen. An all-in-one computer doesn’t need one, since the display and computer components are combined in one unit.
Can you use a TV as a computer monitor?
A TV with an HDMI input can work as a computer monitor. However, a TV is usually designed for viewing from several feet away, so text may look less sharp up close. Some TVs also add more input lag than a computer monitor, which can affect gaming and mouse responsiveness.
Do computer monitors have built-in speakers or webcams?
Some computer monitors include built-in speakers, and conferencing monitors add a webcam and microphones for video calls. Many monitors have neither, so check the specifications if built-in audio or a camera matters to you.
