the tuner is somewhat more complex: in addition to a part analogous to the analog tuner, in fact, will contain a circuit to further process the signal so as to distinguish depending on other parameters characteristic of the signal:
polarization (in the case of satellite TV),
number of symbols per second (symbol rate, also referred to with S / R),
Forward Error Correction (FEC) for channel decoding.
Program Information Data (PID) SINGER 7256
This multiplicity of parameters, together with the possibility of the digital data to be compressed in the transmission (source coding), makes it possible to transmit within a frequency band similar to that analogue not only a channel but also 4, 6, or even 10 (see also digital TV and DVB);
the screen, finally, can be essentially of three types: the classic cathode ray tube, initially present in all the television sets, but subsequently joined by other technologies; plasma, liquid crystal, more recently OLED (Organic Light Emitting Diode), or working with tiny light-emitting diodes (LEDs) and since 2008 that required for the laser monitor. Each type of screen also has a so-called aspect ratio ie the ratio between the long side and short side.