The first three characters tell you in what country the vehicle was built. The fourth through eighth character tells a lot about the type of car, it's chassis and model. The ninth digit is called a check digit which essentially is added for redundancy and to catch any identification errors that may have occurred in the letter and number sequence. The last characters, number tenth to seventeen tells more about the vehicle, it's engine and/or transmission, etc. Each manufacturer uses it's own set of numbers and letters for descriptive purposes.