Set-Top Box +
A set-top box (STB) or set-top unit (STU) is an information appliance device that generally contains a tuner and connects to a television set and an external source of signal, turning the signal into content which is then displayed on the television screen or other display device. Set-top boxes are used in cable television and satellite television systems, to transform the signal from the cable or satellite to a form that can be used by the television set or other receiver. It also enhances the quality of signal from cable or satellite.