Have you ever got up from watching your favourite show to get a drink or go to the loo only to have missed 3 or 4 minutes of the show? With Personal Video Recorders or some models of TV you can pause and rewind live TV and never miss a thing.
These features use hard drive or flash drive storage inside the PVR or TV. If you watch a show through your PVR instead of on an ordinary Digital TV you can press pause at any time and the PVR continues to record. You can also press rewind any time and it will allow you to rewind back as far as the point where you changed to the channel.
This is just another reason to get a Personal Video Recorder to use with your Digital TV. As mentioned earlier some new Digital TVs also have this feature, but you should check to see what capabilities it actually has before buying. There are however some quite inexpensive PVR units that can do it.