Like all digital images, remote sensing images are composed of a series of individual picture elements, known as pixels. Each pixel is displayed on your computer screen as a specific color, and it is the combination of these pixel colors throughout the image which produce the picture of your house, your puppy, or your family that you see in a digital picture.

The size of pixels in an image is determined by your camera or the remote sensor at the moment the image is captured. Images are meant to be viewed at a zoom level where the individual square pixels are not apparent; they are supposed to blend together unnoticeably to form a picture. When you use image viewing software to zoom in to a digital image, the pixels in effect get "closer" to you, and it becomes easier to see the actual squares. At a certain zoom level, each pixel will look so large on the screen, and so few pixels will be displayed at one time, that the picture displayed in the digital image will cease to have any meaning.