The main functions of locking systems in vehicles are theft protection for the vehicle and the luggage, as well as the safety of the occupants during the journey. Basism models consist of the door lock, a door inside and a door handle. Depending on the model, door handle sensors, child safety devices, alarm systems and immobilizers are available. Modern crash locks allow automatic closing of the vehicle doors in the event of an accident in order to ensure that the occupants are not thrown out of the vehicle or are additionally endangered by raised doors. Depending on the model, acoustic-visual displays of the closed state, remote controls and modern keyless entry systems are available to replace the previously mandatory key with a chip card.