The documentation certifying ownership of a vehicle will be in the form of a V5 Certificate. These documents are also commonly known as the "Logbook". The document currently has 2 versions in circulation. Which document your vehicle will have depends on when the last change of ownership was completed or the age of the vehicle. The V5 Certificate is the official ownership document issued by the DVLA.
For further information on this document and how they relate to your car please click here.