Vehicle Identification Number is a 17 digit unique identification sequence present on every vehicle. The VIN is used by the vehicles for identification purposes. The VIN is a distinct code offered to every vehicle, so two different vehicles cannot have the same VIN.
When you are filing your Form 2290, the IRS requires you to provide the VIN of each vehicle you are filing. The VIN of a vehicle can be found in the registration or title documents, or the actual vehicle.