wrote
A DVR is basically just a PC (in a small case with a special
interface) that records TV on a hard drive. When they say they can
record more than one channel that means they have more than one tuner.


Everything goes to the hard drive and is then sent to the TV. That is how it
allows you to pause, rewind, FF, etc. When you change channels, it is not
instant, but the ability to do those functions makes it a vey nice toy to
have.