Picture this. A computer is made up of millions of electronic switches (transistors). They're either on or off, open or closed.
Now picture this. Your computer screen has hundreds of thousands of dots arranged in rows and columns. Each dot is a picture element or pixel. Each of these pixels displays some combination of red/green/blue according a device called a Video Graphic Array (VGA) The VGA translates binary-coded information (0s and 1s) into the color combinations required to make up an image on your computer screen.