A:

One of the main features of this model is that it has a Built-In ATSC/NTSC/QAM digital tuning wherein it allows you to view or tune to standard cable channels as well as off-air digital broadcasts, in addition to digital "cable-in-the-clear" broadcasts.

As for your question about HDMI (High-Definition Multimedia Interface), it is basically a type of cable to be used for HD TVs. It is a compact audio/ video interface for transmitting a full digital data from source to destination (e.g. player to TV).