Function

• Set top boxes are equipped with internal TV tuners, an electronic devices used to receive and decode TV signals. A digital smartbox is a device used to decode incoming digital TV signals. A digital HD DVR, on the other hand, is a high definition digital video recorder used to record digital quality video to an internal hard disk.
  
  

Combination

• A digital smartbox DVR combines the digital tuning function of a smartbox and the digital recording function of a DVR intp one device.
  
  

Use

• In order to use a stand alone digital HD DVR to record video, the DVR has to be hooked up to a set top box (such as a digital smartbox) because standalone DVRs are not equipped with internal tuners. If a device is a combination digital smartbox DVR, a separate set top box is not required to record video.