Digital TV or Digital Video Broadcasting, is a set of standards for the transmission of digital video and audio.
DVB consists of a data packets, which carries MPEG2 coded video/audio and EPG combined with other pay load. The data for each channel is identified by PIDs. Depending on the transmission path there a four different kinds of DVB, which have different modulations, frequencies, bandwiths and resolutions.
DVB-C (digital cable TV)
DVB-T (terrestrian digital TV)
DVB-H (a new standard for mobile equipment, e.g. mobile phones)