set-top box

The cable TV box that sits on "top" of the TV "set," although it is often located several feet away in an equipment rack. The set-top box descrambles the premium channels and provides a tuner for the higher cable numbers that very old TVs did not support. Originally only for analog TV signals, set-top boxes have become widely used for digital services that offer an on-screen program guide. Digital set-top boxes that provide high-definition TV (HDTV) are the latest version.

With satellite TV, a device similar to the set-top box decodes signals for viewing. However, although some call it a "satellite set-top box," it is officially known as a "satellite TV receiver."

Built-In DVR
Some digital set-top boxes have a built-in hard drive for recording programs. The advantage of having a combination set-top box and digital video recorder (DVR) is the integrated, on-screen program guide. The familiar interface for selecting channels is also used for recording. See DVR.

Internet Access
Although the cable itself supports TV and Internet transmission, the traditional set-top box does not provide Internet access. Where it enters the house, the cable is divided into two using a small, passive device called a "splitter." One line goes to the set-top box, and the other is fed to the cable modem. See hybrid set-top box and cable modem.

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(communications, networking)

set-top box - (STB) Any electronic device designed to produce output on a conventional televesion set (on top of which it nominally sits) and connected to some other communications channels such as telephone, ISDN, optical fibre or cable. The STB usually runs software to allow the user to interact with the programmes shown on the television in some way. Online Media are one STB manufacturer.