What are pixels? Defining a Pixel, Screen Resolutions, Aspect Ratios and DPI explained

A pixel: short for picture element, and abbreviated to .px, is a unit of measurement in digital imaging. It is the smallest part of an image that it is possible to singly edit. Individual pixels (that collectively make a raster image, in rows and columns) are identical in size but vary by specific shades of colour, which can be digitally identified using an eyedropper tool to get the hex code.

The more pixels that an image contains, the more data that the file stores, which means that the file size is likely to be larger.

Although you can find pixel calculators online, the actual measurement of a pixel varies, dependent on the resolution of the screen that it is being viewed on. 

What is a computer screen resolution?

You may have heard the term 4k or 1080p in relation to TV screens, and if so then you are probably already aware that the higher the number, the better quality the image.

Resolution measurements, were formerly shortened to the pixel count taken from the shortest (usually vertical) side — (1080p is actually a screen resolution of Height: 1080 pixels x Width 1920 pixels). Since 4k, the 4000p measurement was taken from the longest (usually horizonal) side.

what is computer screen resolution


If you are a Windows operating system and want to check your own computer screen resolution, you can do this by right clicking on your desktop background and going into the Display settings. 

What is an Aspect Ratio?

Ratios are a common way to show proportion. You may be familiar with them from adapting recipes to suit the amount of people that you are cooking for, or in the form of betting odds at a bookmakers.

The aspect ratio is simply relating to the ratio of the width compared to the height of a screen or an image.

For example, we could easily identify that a ratio of 1:1 was a square, and a ratio of 2:1 was a horizontal rectangle that was twice as wide as it is high.

What does DPI mean?

In computing and printing, DPI stands for Dots Per Inch. This could either be in reference to an image you would like to print, or your DPI for a computer mouse.

For printing purposes, it relates to how many dots of ink will be present per square inch. So a 300 DPI setting would print at higher quality than a 72 DPI setting.
(That's over 4x more dots per inch, therefore over 4x higher quality).

DPI for a mouse relates to how many dots per inch that the cursor is crossing, therefore the higher the value, the faster the speed that your cursor moves across the page. You can change this speed in your mouse settings.



If you found this blog helpful, please check out our newly-created Facebook crafting community here, where we will be sharing tips and advice, plus a free SVG bundle once a month.

Back to blog

Leave a comment

Please note, comments need to be approved before they are published.