What Is A Computer Monitor?

Date First Published: 2nd July 2023

Topic: Computer Systems

Subtopic: Computer Hardware

Article Type: Computer Terms & Definitions

Difficulty Level: 1/10

Learn about what a computer monitor is in this article.

A monitor is a basic output device that receives and interprets signals from the graphics card of the computer and displays it in the form of graphic images, videos, and text, providing real-time feedback as users work or play. Monitors are used in combination with keyboards, mouses, and touchpads to allow users to interact with a computer and view data.

In order to render an image on a monitor, the CPU sends the image data to a GPU, which translates the image data into bitmaps, which are then transmitted onto the display. This causes the GPU to perform computationally intensive functions to ensure that the monitor exactly represents the screen image.

Note:

The term monitor is most commonly used synonymously with 'screen' or 'display'.

Types Of Monitors

Below are three different types of monitors, based on the technology they use to display graphic images, videos, and text.

• Cathode Ray Tube (CRT) monitors - These types of monitors use specialised vacuum tubes which emit manipulated electron beams to display images on a phosphorescent screen. CRTs are big, bulky, deep in size, consume more power, and look like old-fashioned TVs. Although they are rarely used now, the CRT used to be the most commonly used type of monitor.
• Liquid Crystal Display (LCD) monitors - An LCD monitor uses liquid crystal sandwiched between two panes of polarised glass, with a backlight illuminating the glass. LCD monitors have replaced CRT monitors due to the better graphics quality, less power consumption, and smaller size.
• Light-emitting diode (LED) monitors - An LED monitor uses an array of light-emitting diodes as pixels for the video display rather than the types of backlights used for LCD monitors. LED technology is usually lighter and smaller than the original LCD.

How Are Monitors Connected To Computers?

A monitor is a separate device connected by a cable to a port on the video card or motherboard of a computer on a desktop computer. It plugs into the VGA, HDMI, or DVI port. In order to support multiple monitors at once, some computers may have multiple ports. The data cable is what allows the picture from the computer to be displayed.

In laptops and all-in-one desktop computers, monitors are built-in. They are integrated as part of the device. However, a separate monitor can be connected to those devices.

Can A Computer Work Without A Monitor?

Without a monitor, a computer can still turn on and function. However, it would be quite useless as there would be no way of knowing what the computer is doing. A monitor is required to see the data users are working with and the effects of the inputs coming from input devices, like keyboards and mouses.

Difference Between A Monitor and A TV Screen

Some people confuse computer monitors with TV screens. Although they both display graphic images, videos, and text and a TV screen can be used as a monitor, they have slightly different features. Unlike TVs, most computer monitors do not have built-in speakers, TV tuners, or remote controls. Another difference between a monitor and a TV screen is the size. TV screens are usually much bigger than monitor screens and have more advanced image processing capabilities.

Important Monitor Measurements

Screen size

One of the most important aspects of a monitor is its screen size. The screen size is the amount of available space to display an image, video, or text without any obstruction from the front bezel. Screen sizes are measured in diagonal inches, which is the distance from one corner to the opposite corner diagonally. Most computer monitors range from 19 to 34 inches diagonally.

Resolution

The resolution of a computer monitor measures the number of pixels that can be displayed horizontally and vertically. It is usually quoted as width x height, with the units in pixels. For example, 1024 × 1366 means the width is 1024 pixels and the height is 1366 pixels. This can indicate how closely packed the pixels are.

Aspect ratio

The aspect ratio is the ratio of the width to the height of a monitor. Like any ratio, it is displayed as two numbers separated by a colon. The most common aspect ratios are 4:3, 16:9, and 21:9. This indicates the relationship between the width and height of the monitor and is calculated from the width and height of the display, measured in inches or centimetres.

Performance Indicators

Other performance indicators that determine the quality of a monitor include:

• Contrast ratio - The ratio of the luminosity of the brightest colour (white) to the darkest colour (black) that the monitor can display.
• Colour depth - The number of bits used to indicate the colour of a single pixel. The more bits per channel (bpc), the more shades of colour that can be displayed without dithering (altering).
• Refresh rate - The number of times per second that the display is illuminated (refreshed). In LCDs, it is the number of times the image can be altered per second, measured in hertz. Ideally, the refresh rate should be at least 72 hertz to avoid flickering.
• Dot pitch - The distance between two pixels next to each other. The smaller the dot pitch, the sharper the image.
• Response time - The amount of time a pixel takes to change between two shades of colour.
• Input latency - The amount of time it takes for a monitor to display an image after receiving it, measured in milliseconds.
• Viewing angle - The maximum angle that images without excessively degrading to the image.

Comments