What is DVR & How it works?
The cameras used by a DVR system must be analog security cameras, better known as CCTV cameras. Most of the cost savings found by using a DVR system is due to the camera. While you can mix and match cameras in your home security system, there is less flexibility in the type of cameras you can use with DVR systems.
In a DVR system, the analog cameras stream an analog signal to the recorder, which then processes the images.
A CCTV digital video recorder (or “DVR” for short) is essentially a computer that saves security video images to a hard drive. Most security cameras in use today capture an analog picture. The DVR converts the analog signal to digital and then compresses it.
Many cameras can be connected to one DVR. DVRs generally come with 4, 8, 16, or 32 camera inputs. The DVR will allow you to view all of these images at once or one at a time, and all of the video is saved to the hard drive. Additional switches, quads, or multiplexers are not required.