The DCT-6028 is a single tuner HD-DVR. It is capable of recording a single channel at a time. You must be watching the channel you are recording or watching a prerecorded program.

The DCT-6412 is a dual-tuner HD-DVR. It has 2 built in tuners and is capable of recording 2 channels, or record 1 channel while viewing another at the same time.