A pixel is the basic logical unit in digital graphics. Pixels are combined to form a complete image, video, text or any visible thing on a computerdisplay.

A pixel is also known as a picture element.



A pixel is represented by a dot or square on a computer monitor display screen. Pixels are the basic building blocks of a digital image or display and are created using geometric coordinates. Depending on the graphics card and display monitor, the quantity, size and color combination of pixels varies and is measured in terms of the display resolution.

For example, a computer with a display resolution of 1280 x 768 will produce a maximum of 98,3040 pixels on a display screen. Each pixel has a unique logical address, a size of eight bits or more and, in most high-end display devices, the ability to project millions of different colors.

The pixel resolution spread also determines the quality of display; more pixels per inch of monitor screen yields better image results.

Screen pixels


In the picture below is an example of a close up of pixels on an LCD screen. As can be seen in the picture, we've zoomed into the "he" part of the word "help" to give a better understanding of how the display works. With this display, each pixel is made up of a red, green, and blue (RGB) light that is increased or decreased in intensity to make up each of the colors you see on the screen.

These days, each pixel is usually composed of three or four colors that glow in unison, with varying intensities, to produce the required ‘combined’ color output. Based on the system used, the pixels may be composed of either Red, Green and Blue or Cyan, Magenta, Yellow and Black.

The smaller screens on the right of the image have the same number of pixels as those on the left, but are only half the height and width. Their resolution is thus twice as high, because there are more pixels per inch of screen area. Pixels do not have a fixed size. Their size is relative to the screen's resolution

What is the resolution of a graphic?

Refers to the sharpness and clarity of an image. The term is most often used to describe monitors, printers, and bit-mapped graphic images. In the case of dot-matrix and laser printers, the resolution indicates the number of dots per inch.

Pixel Density is usually measured in PPI (Pixels Per Inch) which refers to number of pixels present per inch on the display. Higher the pixel density higher is the sharpness of the content. Pixel Density is calculated based on the resolution and size of the display. Consider the above image.