Digital TV is where the content is sent as a digital video stream, rather than an analogue stream. This allows it to:
- make better use of the available bandwidth, allowing for more channels to be broadcast or less radio spectrum to be used
- offer multiple audio and video streams per channel, eg: surround sound support and translations into other languages
- better picture quality through higher resolution and the ability to recover from some transmission/reception errors
Commonly referred to as DVB (Digital Video Broadcast), it can be supplied over different bearers: terrestrial (DVB-T), satellite (DVB-S) and cable (DVB-C).
DVB is often combined with internet functionality into things like Hbb-TV, which allows for consumers to easily move between live broadcast channels and on-demand content supplied via an internet connection. Freeview in New Zealand uses Hbb-TV, and is broadcast over both terrestrial and satellite bearers, with on-demand video available for the major channels.
Cable TV may or may not be digital depending on the provider.