The most common computer output device is the monitor or computer screen. Monitors create a visual display for you to view from processed data. They come in a variety of screen sizes and visual resolutions. There are two common types of modern computer monitors, cathode ray tube and flat panel screens. CRT monitors use phosphorescent dots to create the pixels that make up displayed images. Flat panel monitors usually use liquid crystals or plasma to create output. Light is passed through liquid crystals to create the pixels. All monitors rely on a video card that is located on the computer motherboard or in a special expansion slot. The video card processes the computer data into image details that the monitors can display.