What is a Monitor? Various Types Of Monitors Explained

Computer monitors have evolved over the years, and image quality has followed suit. This article will explain what a monitor is and the different types of monitors you can get.

We will also explain more about the various types and how they connect to a computer. The connectors also evolve to keep up with the demands of newer display technology.

What is a monitor?

Three types of monitors. CRT, LCD, and a portable USB C monitor.
A CRT, LCD, and Portable Monitor

A monitor is a display device like a TV screen that interprets and displays the graphical output signal from your computer’s graphics card and displays it on the screen.

This lets you view the display interface to interact with the computer using various peripherals like a mouse or keyboard from output devices like graphics cards.

Different types of monitors and how they work

Knowing about the different types is beneficial to better understand what a monitor is.

Now that we know that a monitor is an output peripheral that graphically displays the computer’s data or processed output video signal, we can see how they differ.

Display technology in various applications has evolved, sharing the same base technology.

Both the television and computer screen started using the vacuum CRT (Cathode Ray Tube).

CRT Monitor

An example of a CRT computer monitor.

This type of monitor requires more power and electronics to operate. A lot of the analog circuitry was cumbersome and took up a lot of space with a small screen by today’s standards.

How they work depends on the type of CRT components and how they work together to deliver a similar result.

The complete outline of how a CRT monitor works would be a full article, so I will try to keep this as brief as possible.

A CRT (Cathode Ray Tube) monitor works by taking the information from the various electronic PCBs that have processed the incoming signal from the computer’s display card.

From there, processing and splitting up the colors with a signal sent to the CRT tube base board connected to the back of the CRT tube.

Electron guns for each color fire electrons onto a phosphorous area for the specific color related to it.

The inside of a CRT screen with the main parts identified.

Impractical aspects

The CRT requires a certain distance between the screen area and the electron guns at the end of the neck, leading to a part of the heavy space requirements.

So apart from being heavy, bulky, and harsh on your eyes, they actually have a decent viewing angle.

The other obvious downfall is the obvious fact that these types of monitors couldn’t be used for a laptop.

Common CRT resolutions

Here are some of the common resolutions for CRT monitors based on display size:

CRT Monitor SizeCommon Resolution in Pixels
17 Inch (4:3 Aspect Ratio)800 x 600
19 Inch (4:3 Aspect Ratio)1280 x 1024
20 Inch (4:3 Aspect Ratio)1600 x 1200
20 – 22 Inch Widescreen (16:10 Aspect Ratio)1680 x 1050
24 Inch Widescreen (16:10 Aspect Ratio)1920 x 1200

Computer monitor burn

CRT monitors are well known to have fixed display elements from the computer to eventually burn into the phosphor coating inside it.

Some LCD screens aren’t impervious to it but are far less common than CRTs. This inspired the birth of the screen saver back in the day.

The screen saver displayed graphics that moved around on the monitor to avoid screen burn-in.

LCD Monitor or TFT Monitor

An LCD monitor rendering.

LCD (Liquid Crystal Display) Monitors replaced the CRT. Initially, they had performance issues to do with response times, but eventually, those problems were solved.

Liquid crystal molecules are placed between two electrodes. The amount of light that can pass through the liquid crystal molecules is determined by the amount of electrical charge applied to the electrodes.

LCD Monitors require backlighting to illuminate the image for us to see. This backlighting technology has also undergone some revolutionary changes.

In the beginning, CFL(Compact Fluorescent Lamps) were used. Inverters were used to step up the voltage to power them up and ended up being a common component that failed over time.

Thankfully, the CFLs were replaced with LEDs. This made LCD monitors way more reliable.

We will go into the various backlight technologies further down in this article.

Common types of Active Matrix LCD monitor panel type:

IPS Panels

In-Plane Switching panels were created to solve the poor viewing angles and low quality color of the TN panels.

They are more commonly used in professional environments because of the refresh rates, but this monitor panel type isn’t best for gaming.

But when it comes to image quality, it delivers great results. And, it comes with a little extra on the price.

The response times are faster than VA panels but slower than TN panels.

TN Panels

Twisted Nematic panels are the most commonly purchased by consumers. They deliver reasonable response times at a reasonable price.

Common LCD monitor styles

There are different styles of LCD monitors that are designed for use in different industries.

  • Rackmount: Designed to mount onto standard 19-inch racks, they can be done as fold away or fixed rackmount style, depending on your needs.
  • Desktop: A standard computer monitor that uses the default stand provided by the manufacturer.
  • VESA Mount: A standard mount of either 75mm x 75mm, 100mm x 100mm, or 200mm x 200mm for mounting to brackets for swiveling or wall mounts. Many standard monitors have these mounts built into the back of them.
  • Panel mount: A flat mounting style with a flange designed to be mounted in a cut-out of some kind, like a wall, to mention one example.
  • Open frame: These monitors are designed with multiple mounting options created on a metal or aluminum frame. These monitors are ideal for products such as kiosks, arcade video games, or interactive music systems.

As you may have noted, monitors come in various designs for many applications.

Common LCD resolutions for desktops

Here is a list of common native resolutions for LCD panels of various sized and aspect ratios:

LCD Monitor Size and Aspect RatioCommon Native Resolution (Pixels)
15 Inch (4:3)1024 x 768
17 Inch (5:4)1280 x 1024
19 Inch (5:4)1280 x 1024
20 Inch (4:3)1600 x 1200
17 Inch Widescreen (15:9)1280 x 768
19 Inch Widescreen (16:10)1440 x 900
21 – 28 Inch Widescreens (16:9)1920 x 1080
29 Inch Ultrawide (21:9)2560 x 1080
30 Inch Widescreen (16:10)2560 x 1600
32 Inch Widescreen (16:9)3840 x 2160
34 Inch Ultrawide (21:9)3440 x 1440
38 Inch Ultrawide (12:5)3840 x 1600
49 Inch Ultrawide (32:9)5120 x 1440

LED Monitor

Light Emitting Diode monitors are essentially LCD monitors with LED backlighting to illuminate the LCD image.

Personally, I’m not a fan of this name for this type of product. If it is truly an LED monitor, shouldn’t the pixels themselves be produced by an LED itself?

When we further discuss OLED monitors, you will see that its name is better suited than this common general term.

QLED Monitor

QLEDs or Quantum Dot Displays are used to convert the backlight to emit pure basic colors.

These semiconductor nanocrystals are placed in a Quantum Dot layer in order to help RGB color filters by reducing light losses and color crosstalk.

Electro-emissive versions are in their experimentation stages. This means that by applying an electric current to inorganic nano-particles, a pixel is formed by a Quantum-Dot Light Emitting Diode (QD-LED).

This would allow for great color ranges and near-perfect black levels on the display.


Instead of being a transmissive technology where the light source comes from an array of LEDs, for example, this emissive technology actually uses organic light-emitting diodes as the light source and displays each individual pixel independently.

These OLEDs are produced as an emissive electroluminescent film of organic compound which lights up when it receives an electric current.

These matrices of OLEDs can be driven either with an active matrix (AMOLED) or via a passive matrix (PMOLED). Active matrices allow for independent control over each OLED, whereas a passive matrix is controlled in rows and columns.

Other types of monitors

Of course, the list extends past what has been mentioned. They aren’t very widely used or have been passed over with other technologies.

However, here is a list of some other monitor technologies:

  • Plasma Screen.
  • DLP or Digital Light Processing.

Different types of video connectors

Here are some typical video input connectors you will find on the back of monitors.

These connections allow your monitor to connect to your computer’s graphics card to display information.


A VGA connector plug.

Video Graphics Array, or more simply, 14 or 15-pin VGA, is an obsolete technology. It has been around for a long time, but an analog video signal is no longer the desired standard. It is not able to carry an audio signal.


A male DVI plug.

Digital Visual Interface is a digital video signal connector that is used not only in monitors but in other consumer electronics too.

Dual-link DVI (29 pins) carries twice the data rate compared with that of single-link DVI (23 pins). This has allowed for higher resolutions and refresh rates.

Dual-link has a maximum data of 9.90Gbit/s @ 165 MHz.

No audio signal can be carried over this connection.


An HDMI plug.

There are 5 types of High-Definition Multimedia Interface connectors:

  • Standard (A)
  • Dual-Link (B)
  • Mini (C)
  • Micro (D)
  • Automotive (E).

This is a replacement for analog video standards and can transmit uncompressed video data and compressed/uncompressed audio data.

Incremental versions have arrived over time with improvements.

HDMI (a 19-pin connector) is used in a broad variety of consumer electronics, even when it comes to computers.

Version 2.1a is capable of delivering a maximum total data rate of 42.5Gbit/s.


A display port plug.

DisplayPort is more commonly used in the computer market, rather than in general consumer electronics.

The latest version, 2.1, has a maximum total data rate of 77.37Gbits/s.

Commonly, DisplayPort comes in two sizes, the standard size, and a Mini DisplayPort.


A Thunderbolt plug.

The previous versions (v1 and v2) use the same connector as a Mini DisplayPort.

The latest Thunderbolt version 3 & 4 uses a standard USB-C connector.

Thunderbolt combines PCI Express and DisplayPort into 2 serial signals and provides DC power.


A USB type C plug.

USB C Monitors are quite new to the market and tend to be a popular trend for mobile monitors.

For example, you will most likely need a cable that can connect your monitor from USB C to Display Port or HDMI.

Two different styles of power connectors

A power brick or power supply for a monitor.
External Brick Power Supply
A standard IEC power plug is connected to a monitor.
Internal Power Supply Using An IEC Mains Cable

Some monitors are built with internal power supplies, and others rely on external power bricks.

Those with an internal power supply usually require a power cable that goes straight from the mains power to an IEC plug that plugs directly into the back of the monitor.

For displays that require an external power supply, power goes from the wall socket into the power brick.

The power brick steps down and converts the mains supply to DC. It is very common for the monitor to run off 12 Volts DC.

While the external power brick makes life a bit harder when it comes to cable management or keeping things tidier, it has one major advantage.

Quite often, monitors go faulty because of a fault in the power supply. It’s way easier and cheaper to replace a common power brick than to get the whole screen repaired or replaced.

The advantage is that by having components crammed inside the monitor, the internal operating temperature should be reduced.

Aspect Ratios

The aspect ratio is the horizontal width of the display with respect to the vertical height.

Different types of aspect ratios are used for different applications.

Multi-Monitor Arrangements

Computer graphics cards have the capability to output to multiple monitors at once and span the display across them to treat them as a single one.

This is particularly nice for gaming.


For some types of professionals, monitors are physically rotated 90 degrees so that the screen is vertically taller than wide.

One example is to help computer programmers see more code at once. Not all programmers do this, just thought I’d mention that.

Some monitor models have this capability built into them, so no modifications are necessary.


The resolution is specified by the number of pixels starting with horizontal and followed by vertical.

For example, 1024×768 means that the resolution contains 1024 pixels in width and 768 pixels in height.

Pixel pitch

Pixel pitch is the amount of space between each pixel. This greatly impacts the quality of an image on a screen.

If the pixel pitch is too large, it won’t matter how high the resolution of your monitor is, the image will be poor.

Refresh rate

The refresh rate is the number of times the entire screen can be updated per second.

For example, if the screen has a 60Hz refresh rate, the screen can be fully drawn 60 times in one second.

Nowadays, a 144Hz monitor is more common and doesn’t affect the overall price of a computer monitor as much anymore.

Response Time

This is the rate at which a pixel can be changed from black to white or from one shade of grey to another.

While you can count the rate at which other color shades of pixels change, black, grey, and white are most the extreme opposites in contrast with respect to each other.

Therefore, they will be noticed first.

Response time is usually written on the millisecond scale.

Desirable response times are anything starting at 5ms or lower.

Touch screen monitors

Touch screen monitors are used in many commercial and industrial sectors and for personal use.

From point-of-sale devices to laptops and desktop monitors, touchscreen monitors offer a different way to interact with a computer.

It can replace the need for a mouse in some cases but can require a need for a larger DPI for a user interface if no stylus is available.

Touch screen monitors are essentially standard LCD monitors with a touch screen glass panel mounted over them.

These glass overlay panels have a few different types of touchscreen technologies. We will cover the different types and some advantages and disadvantages.


Simply put, resistive touch screen panels are glass panels with two striped electrode plastic sheets and a center separation sheet with a grid of holes allowing the two out sheets to make contact through the holes when the panel is touched.

This is the least robust out of all the panels, as wearing eventually makes it unreliable. The quality of the display can also be affected as the plastic surface develops scratches over time. One advantage is that it will work with gloves.


There are four common types of capacitive touch screen technologies. Here is an outline of each one. All capacitive technologies are quite robust and will offer a good long-lasting product.

Surface Capacitance

Capacitance is formed from a finger that touches an uncoated surface with the other side of the glass panel that has a conductive layer.

Good finger contact is required for best results. These types of panels must be properly calibrated and can be sensitive to improper grounding, background noise, and temperature fluctuations.

Projected Capacitance

PCAP capacitive panels with an etched single conductive layer form a grid pattern of electrodes that processes touch using a more sophisticated firmware program to decode the touches.

Moisture or dirt particles can interfere with the operation, so it is not always the best choice for some applications.

Mutual Capacitance

A grid is laid out with a voltage that is applied to the rows or columns to detect a conductive element such as your finger or conductive stylus.

The detection works by picking up a change in the conductive field in the grid.

This kind of panel is good for multi-touch purposes, where it can simultaneously detect two or more contact points.

Self Capacitance

Self-capacitance panels are laid out very similarly to mutual capacitance panels. But the X and Y parts of the grid can operate independently.

The capacitive load is measured on each column or row by using a current meter or an RC oscillator to detect a change in frequency.

This kind of panel is very sensitive to touch and is great for multitouch applications like tablets and smartphones.


An array of sending and receiving infrared LEDs is placed along the inside of the frame or bezel of a monitor to detect a disruption between them.

However, this is not a very reliable technology and is highly sensitive to dirt blocking the path of the infrared light causing false positive touches.

Optical imaging

With optical imaging touch screen panels, image sensors are placed in the corners at the edges of the screen, and a touch blocks the infrared backlight’s light in the sensor’s field of view.

These types of touch screens are becoming more popular for larger displays.

In conclusion, to touch screens, there are more technologies available on the market, and the list is growing.

Curved Displays

An example of a curved computer monitor.

There are pros and cons to curved displays. In my opinion, you need to try one out to see if it’s something for you or not.

These curved monitors can offer a slightly more immersive experience when it comes to gaming but can be a bit more expensive compared to traditional flat panels.

Computer monitor energy consumption

Power consumption has been reduced considerably since CRT displays have fallen away.

Now, a common desktop computer monitor consumes between 60 and 250 watts of power. In standby mode, roughly between 1 and 6 watts.


And there you have it. You know what a monitor is, and more than that, the different types.

I hope you enjoyed the information and knowing more about them.