Tuner - It's the electronic portion of a digital TV, set-top box, media center or other electronic device that 'catches' the incoming signal from the viewer's antenna. However more has to be done to the signal before it's viewable. See Decoder. It can also be used to 'catch' standard analog TV signals. A receiver includes the tuner and has additional functions.
  The tuner might be used for accessing QAM, OFDM and QPSK networks, as well as being able to receive data in digital form.

The below might be used to describe set-top and integrated tuners:

1) Broadcast In-Band (IB) - For this the tuner separates a channel from all the channels received and converts it into a single signal that the receiver makes viewable.

2) OUT Of Band (OOB) - It can offer more interactive services.

3) Return Path Tuner - This type of tuner, or mechanism of a tuner, allows more readily the return of interactive data to a signal's source.