(plural set top boxes)
- A device that converts an incoming signal into a format displayable by a television.
set-top box - Computer Definition
A small computing device that interfaces a television (TV) set or computer to a cable TV (CATV) network, cable modem network, or satellite TV dish and, perhaps, telephone network. A set-top box is responsible for functions such as decoding digital TV signals for display on an analog TV set, compression and decompression, buffering, security management, and various signaling and control communications. See also analog, buffer, cable modem, CATV, compression, digital, encoding, security, and signaling and control.
A device that converts video content to analog or digital TV signals. For years, the set-top box (STB) was the cable box that "sat on top" of the TV. Although no more flat surface to rest anything, the term lives on. A satellite TV set-top box is officially a "satellite receiver," and the box that converts over-the-air digital broadcasts to analog for old TVs is a "converter" (see TV converter box). Apple TV, Fire TV, Android TV and Roku boxes connect to the home network for Internet access and convert video from Netflix, Hulu and other providers into TV signals. These "media hubs" go by many names and may accept local content from the home network as well (see digital media hub). The Cable Set-Top Box In the days of analog TV, cable boxes descrambled the premium channels and managed the high channel numbers old TVs did not support. For today's digital service, the cable box decodes MPEG video frames, decrypts the premium channels and stores and displays the program guides. Also providing upstream communications for video-on-demand, digital cable boxes often have a built-in DVR for recording content on a hard disk. Many cable TV companies also offer Internet service, but their set-top boxes are only for TV. The cable coming into the house is split into two lines: one to the set-top box and the other to the cable modem for Internet access. See MPEG, DVR, CableCARD, cable modem and hybrid set-top box.