What is screen resolution and why does it matter?

Women working on multiple screens in her home office

Screen resolution is one of those IT terms that people use without necessarily knowing exactly what it means. We thought it was about time we explained what screen resolution is and why it matters

What is screen resolution?

The image on your computer screen is built up from thousands or millions of pixels. The screen creates the image you see by changing the colours of these tiny square elements.

The screen resolution tells you how many pixels your screen can display horizontally and vertically. It's written in the form 1,920 x 1,080. In this example, the screen can show 1,920 pixels horizontally, and 1,080 vertically.

Different screen sizes, same resolution

Now it starts getting a little more complicated. Screens that are different sizes can still have the same screen resolution. Monitors have fallen drastically in price over the years so the temptation may be to go for the biggest display screen you can afford.

But size isn't the only consideration. You could have a laptop with a 15" screen and a resolution of 1,366 x 786. You could also have a 21" monitor on your desk with the same 1,366 x 786 resolution.

In this example, although the monitor on your desk is larger, you won't actually be able to fit anything extra onto it. The total number of pixels is the same - everything just looks a bit bigger:

Screen diagram

This means that choosing the right screen means you have to take note of both the screen's size and its resolution.

What does higher resolution mean?

If you're comparing two screens of the same size but with different resolutions, the screen with the higher resolution (that's the one with more pixels) will be able to show you more of what you're working on, so you don't have to scroll so much.

Because that screen has more pixels, the image will be sharper. However, the higher resolution also means that elements on the screen - like icons and text - will look smaller.

There are more options available than ever when it comes to screen resolution; It is now possible to buy high definition (1,366 x 768), full high definition (1,920 x 1,080), wide ultra extended graphics array (1,920 x 1,200) and even ultra high definition monitors (3,840 x 2,160) also known as 4K.

It's not just about display resolution

When you're choosing a new computer or display monitor, don't let yourself be guided by screen resolution alone. Brightness and colour representation can vary across screens, so the best way to choose is to sit down in front of a screen and see if you like it.

Having said that, there are a few rules of thumb to help you choose the right resolution:

  • If you're buying a monitor for your desk, go for a screen sized 21" or bigger, with a resolution of at least 1,920 x 1,080 or more. This is known as a full HD screen, because the resolution is capable of displaying high definition video.
  • If you're buying a laptop that will be mostly used with a separate monitor, the standard screen should be fine. Higher resolution laptop screens can increase costs significantly, and aren't worth the expense for occasional use.
  • People who do graphic design work or need to access lots of different windows at once (like web developers) can benefit from specialist, high resolution screens. If you're feeling flush, Apple's 15" MacBook Pro with Retina display boasts True Tone technology and a high contrast ratio to deliver deeper blacks and more vibrant whites. The LG 27" ultra HD display is one of the best separate displays you can buy.

Written by John McGarvey.

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