digital video recorder (DVR)
A DigitalVideoRecorder(DVR) is a recording device that records video in a digital format on a hard disk or Solid State Drive( SSD). Such devices are used as personal video recorders( PVR).
The key difference with a VCR is that the latter records the video signal in analog format on magnetic tape, while the DVR recorder compresses the video signal using video compression and stores it digitally.
Digital video recorders can record all video formats, from low definition television(LDT) to high definition television( HDTV), depending on the requirements. Since the storage of video and especially HDTV requires extreme amounts of data, DVR devices must be equipped with several hundred gigabytes( GB) up to a terabyte( TB) of storage capacity.
In addition to the Digital Video Recorder and the Personal Video Recorder, there is also the Network Video Recorder( NVR), which stores video data streams digitally.