DVB is the European standard for digital TV, and as such, provides a very high-speed, robust transmission chain capable of many Megabits per second needed for each of several hundred MPEG-2 digital TV channels. DVB sets standards for Satellite transmission (DVB-S), for Cable Transmission (DVB-C) and the Terrestrial Television (DVB-T). The latest DVB standard is for handheld portable device i.e. mobile handsets or PDA called DVB-H. The core system is the same for digital satellite, cable and terrestrial TV with different modulation methods for each mode.
The basic "unit" of the DVB system is the DVB multiplex - a very high speed data stream containing data packets from a number of individual smaller data streams. The parameters can be chosen, so that a DVB-S multiplex that transmitted from a single satellite transponder is the same effective bandwidth as a DVB-C multiplex that is transmitted down a single analogue cable TV channel.
This allows any service contained within a DVB multiplex to pass down any current TV infrastructure to be received on an appropriate DVB receiver , whether satellite or cable.