Monitor is an output device that displays information in pictorial form. A monitor usually comprises the visual display, circuitry, casing, and power supply. The display device in modern monitors is typically a thin film transistor liquid crystal display (TFT-LCD) with LED backlighting having replaced cold-cathode fluorescent lamp (CCFL) backlighting. Monitors are connected to the computer via VGA, Digital Visual Interface (DVI), High-Definition Multimedia Interface (HDMI), DisplayPort, Thunderbolt, etc. Modern computer monitors are easily interchangeable with conventional television sets and vice versa.