Digital video recorder or DVR system may be standalone or could be hooked to a personal computer through a video capture card. Standalone systems are compact and contain the multiplexer , video capture device and storage in a single unit.   Software is incorporated  for control of the cameras and for processing of information.

. Through cascading ( use of multiple DVR ) ,it is possible to connect thousands of Cameras to a single monitoring base system . IP Cameras are becoming quite popular where ever remote observation is desired.

DVR Vendors  :

There are quite a few vendors of digital video recorders. Fairly cheap recorders and video capture cards are being manufactured and aggressively marketed  by Chinese , Taiwanese and Korean companies . A handful of European and American companies are also present . Though the  hardware quality of Asian origin  DVR is comparable with that of the European countries , the issues related to documentation , user manuals and  user interface is found wanting.  Sometimes it may become quite a task to install and commission these devices even by expert technicians   due to lack of installation manuals  or   insufficient  information.