Why require a Dash camera for my vehicle

I am car driver,what a dash cam can help

• You should definitely install a dash cam in your car. Dashcams are gaining popularity and are one of the best ways to prove what happened during a collision with another driver. Almost all drivers now have onboard cameras on their vehicles.
• It has features that most people demand in a dash cam stylish, quality, human-oriented hidden design, ultra HD lens, and allows you to record 4k video quality with (night-vision) & G- sensor (motion detector). In addition, the camera will turn on and start recording on its own and an in-built microphone.
• Dashboard cameras are onboard devices used in private cars, law enforcement vehicles, and rental and other commercial vehicles to record real-time videos both inside and outside of the vehicle.
• The various technologies used in dashboard cameras can be grouped into single lens or single channel, multi lens or dual channel, and rear-view. 

view best dash camera for a car which I can install a rear camera

Dual Camera, Rear Camera can install in back of car, it is also with GPS tracker,

view best dash camera for car which I don’t want to install a rear camera, I want built-in type

Dual Camera ,rear camera is built-in type

I am a trucker driver, what a dash cam can help

• Although truck drivers follow certain safety precautions in their everyday lives, accidents still happen. To help protect truck drivers, every fleet should have tracking system technologies on the road. Regardless of the accident, driving cameras for trucks can help protect drivers from liability and keep them safe!
• Dash cams, or dash cameras, offer truck drivers and fleet managers more control over their fleet safety with features designed to increase visibility, reduce accidents, and lower collision costs. A car camera serves as an indisputable eyewitness to accidents and other driving hazards, providing video evidence to ensure fleets remain safe and non-offending drivers are exonerated.

For a big type vehicle,the camera is better if you adjust the camera capture angle

Here are some model for reference