Digital Set-top Box - Another term for “set-top box” as set-top boxes work as digital units. A set-top box (or equivalent device) to be used in conjunction with an analog device, takes an incoming digital signal(s) and turns it into an analog signal(s) that that analog unit, such as an analog TV, can understand.

Codec

Lossy Compression

Lossless Compression (Nonlossy Compression)

See the Interactive Television Institute.