A liquid crystal display (LCD) is a thin, flat display device which is used commonly as computer monitors. With advances in LCD technology, large screens which are thin and have wide viewing angle are available. A LCD display unit uses very small amounts of electric power and hence is a good choice for battery powered devices.

Two sheets of polarized transparent material, one with a special polymer coating that holds liquid crystals, are adhered together. Electric current is passed through individual crystals, which interpret the information from the broadcast signal to allow or disallow light through them to create an image. The crystals themselves do not produce light, so the technology is "non-emissive" and therefore does not give off radiation like an older television does. Fluorescent tubes housed behind the transparent material illuminate the image. They require less power to operate than CRT and plasma televisions which require powering hundreds of electrodes to stimulate the phosphorous.

The LCD and Plasma display units interface with the in-room equipment (STB) using a RGB input or DVI input for video. The STB controls the display unit using either a RS232 Serial communication interface or a TCP/IP interface to exchange handshake commands for operations like switching ON / OFF, changing channels, changing input selection between TV and AV, volume control etc.