In the simplest case, a video recorder or DVR (from English Digital Video Recorder) it is a compact video camera with a bracket for mounting in a car and a power supply from a socket or cigarette lighter in the car. Most often, the bracket has a suction cup and is attached to the windshield, but there are options for mounting on the rearview mirror or for installation on the dashboard.
If you are mounting it on the windshield, remember that the recorder should not restrict the driver's view. In this case, it is better to place it behind the rearview mirror on the opposite side from the driver.
Almost all modern video recorders record sound through a built-in microphone. Some allow you to connect an external microphone. There are models of recorders that have two cameras, simultaneously recording what is happening in the car, or have the ability to connect a second camera, remember the route (coordinates using the built-in GPS navigator), and even the speed of the car. They can also react to a collision impact, in which case the video fragment preceding the collision is automatically transferred to backup storage and is no longer replaced by new video fragments. Some models of recorders can continue recording after the car is disconnected from the power supply. This will allow you to record the situation not only from inside the car, but also from outside.
If you are involved in an accident, warn the arriving traffic police officer that the incident was recorded by a video camera located in your car. If the inspector does not indicate this fact in the protocol, then make the appropriate entry yourself before signing the document.