While you can use any standard 16x2 alphanumeric LCD, the white on black display supplied with the kit looks übercool. Pixels make up a character space, which is the number of pixels in which a character can exist. The size of displays is often represented in pixels. If you look closely at the characters on the LCD, you will notice that they are actually made up of lots of little squares. This display also has an LED for backlighting, which is powered usually through a basic character LCD pins 15 and 16. The controller datasheet has a diagram of all the characters stored in the chip. A HD44780 controller chip built into the display (it's underneath the black blob on the back) receives commands from your a microcontroller, and turns the pixels on and off to form various letters, numbers and symbols. This affects the way light passes through the dot, allowing it to appear either darkened or clear. Liquid crystal molecules are normally twisted, but straighten out when electricity is applied to them. These displays contain a grid of liquid crystal dots, or pixels held between layers of glass etched with transparent electrodes.