Pixel

Pixel (also known as pel) is an acronym for PICture ELement. Your screen is divided into millions of pixels, which are actually dots of light. A pixel is the smallest unit on your computer screen or in your computer's memory that forms an image.

URLs:

The Single-Pixel GIF Trick

This page explains and offers a single-pixel clear GIF that you can use when programming in HTML to create space around the page.

The Pixel Calculator

The "pixel calculator", shown on this page, was designed to help 12-17-year-olds understand the relationship between pixel value and visual brightness.

W3E References:

screen

binary

Detail:

If a pixel contains only two colors (such as black and white), it can be encoded by a "bit" of information. A bit (BInary digiT) is the smallest unit of information that a computer can have, and it can hold the value of only 0 or 1. On a monochrome screen (one that can display only one color against a light or dark background), a pixel varies only in brightness. On a color monitor, however, each pixel has not only brightness, but also color, created by combinations of red, green, and blue (RGB).