A digital video recorder ( DVR ) or personal video recorder ( PVR ) is a device that records video in a digital format to a disk drive or other memory medium within a device. Most DVR systems include stand-alone boxes, portable media players ( PMP ) and software for personal computers which enables video capture and playback to and from a disk.

   DVR systems have become the main way for closed curcuit television ( CCTV ) companies and     security system providers to record their surveillance as it provides much longer recording times     than the previously used videocassette recorders ( VCR ).