Home : Technical Terms : Resolution Definition


Resolution measures the number of pixels in a digital image or display. It is defined as width by height, or W x H, where W is the number of horizontal pixels and H is the number of vertical pixels. For example, the resolution of an HDTV is 1920 x 1080.

Image Resolution

A digital photo that is 3,088 pixels wide by 2,320 pixels tall has a resolution of 3088 × 2320. Multiplying these numbers together produces 7,164,160 total pixels. Since the photo contains just over seven million pixels, it is considered a "7 megapixel" image. Digital camera resolution is often measured in megapixels, which is simply another way to express the image resolution.

"Resolution" is often used synonymously with "size" when describing the dimensions of a digital image. However, the term "size" can be a bit ambiguous, since it may refer to the file size of the image or its dimensions. Therefore, it is best to use "resolution" when describing the dimensions of a digital image.

Display Resolution

Every monitor and screen has a specific resolution. As mentioned above, an HD display has a resolution of 1920 x 1080 pixels. A 4K display has twice the resolution of HD, or 3840 x 2160 pixels. It is called "4K" since the screen is nearly 4,000 pixels across horizontally. The total number of pixels in a 4K display is 8,294,400, or just over eight megapixels.

Monitor resolution defines how many pixels a screen can display, but it does not describe how fine the image is. For example, a 27" iMac 5K display has a resolution of 5120 x 2880 while an older 27" Apple Thunderbolt Display has exactly half the resolution of 2560 x 1440. Since the 27" iMac is the same physical size as the Thunderbolt Display but has twice the resolution, it has twice the pixel density, measured in pixels per inch, or PPI.

NOTE: Unlike monitor resolution, the resolution of a printer or scanner is analogous to pixel density rather than total pixels. Printer and scanner resolution is measured in dots per inch, or DPI.

Updated: August 26, 2019

Cite this definition:


TechTerms - The Tech Terms Computer Dictionary

This page contains a technical definition of Resolution. It explains in computing terminology what Resolution means and is one of many technical terms in the TechTerms dictionary.

All definitions on the TechTerms website are written to be technically accurate but also easy to understand. If you find this Resolution definition to be helpful, you can reference it using the citation links above. If you think a term should be updated or added to the TechTerms dictionary, please email TechTerms!

Subscribe to the TechTerms Newsletter to get featured terms and quizzes right in your inbox. You can choose to receive either a daily or weekly email.

Sign up for the free TechTerms Newsletter

How often would you like to receive an email?

You can unsubscribe at any time.
Questions? Please contact us.