A Digital Video Recorder (DVR) is designed to record video signals from closed-circuit cameras for detection and documentation. DVR’s have evolved into sophisticated devices that exceed the simple recording of images of VCRs. You may search for an event by time, date, and camera, instead of watching all the video for a particular event. There are many variables including the frame rate, hard drive, and number of cameras. As a DVR records it records over the oldest data first, allowing you to always have the newest data. DVRs usually fit into 2 categories PC-based or Embedded. A PC-based DVR has been modified to capture the images, and an embedded DVR is designed as a digital video recorder.