Handhelds use a liquid crystal display (LCD), the same as the display used in notebook computers. Nearly all handhelds feature a backlit touch screen, with a stylus for tapping commands, selecting items, and writing text. Because the LCD on a handheld makes up most of the front of the unit, you'll want as bright and legible a display as you can afford.
The monochrome LCD, or black and white, is less expensive and more energy efficient than colour. If you don't want to bother with recharging batteries often, a basic monochrome handheld will do.
You can count on colour to be brighter, clearer, and easier to read than monochrome. Colour is also more expensive and can cause shorter battery life. The battery life for a palm-sized colour Pocket PC, for example, is 6 to 10 hours, so you'll need to recharge every few days. Colour is definitely better for games and multimedia, displaying digital still images and in some models short video clips.
The size of the LCD is measured by the number of characters that display across the screen and the number of lines of characters from top to bottom. A typical palm-size monochrome Pocket PC has a display resolution of 320X240 pixels, with grayscale text and images in four shades of gray. Most Palm OS screens display 160X160 pixels, but that differs among manufacturers.
The passive-matrix screen is a type of LCD colour display in mid-level handhelds that provides good colour images viewed straight on. Active matrix, also known as thin film transistor (TFT), is the sharpest, brightest, and most expensive type of handheld display.
If you're opting for a colour display, an active-matrix screen that supports 16-bit colour is optimal because it can display more than 65,000 colours. Look for a reflective screen, which is easier to read in bright sunlight.