A vehicle registration plate is a metal or plastic plate on a motor vehicle or trailer. It is used for official identification purposes. There is a numeric or alphanumeric code that identifies the vehicle. In some countries, the identifier is unique in the entire country. In other countries, it is unique in a state or province. Sometimes the identifier is for a person and sometimes for a vehicle. Each country calls a vehicle registration plate something different. Examples are license plate or tag (US), licence plate (Canada), number plate or registration plate (UK).