A VIN number, or Vehicle Identification Number (typically reffered to as a VIN number even though this is incorrect, much like PIN number) is a 17-digit number stamped into the chassis of a car, that serves as the car's unique identity code.
It is important because it is unique to that car and, unlike registration numbers and other codes, cannot be changed. It is given to a car on the production line and is thus fixed to that car forever.
The first part of the VIN number is the country and manufacturer identifier (for example, ‘WAU’ identifies a German Audi).
The second section is the vehicle description, with the remaining part of the Vehicle Identification Number being the identifier.
