Vehicle Identification Numbers are unique codes given to each on-road vehicle. Each new car is given a standardized 17-digit code, which includes a serial number. Older cars may have VINs too, although they will not follow the standardized formula. A VIN lets you unlock vital information about the vehicle and its history.
You can find a VIN on the car itself and on a variety of documents.
Finding it on the Car
The two most common places are the dashboard and driver's side door jamb sticker. Other places to find it are on the engine and inside the hood.
Finding it on Paperwork
The VIN is always on vehicle title documents. It's also on insurance policies, service records and police reports for the vehicle.