A door handle is used to open and close car doors. It is found on both the exterior and interior sides of automobile doors. Some car door handles can be found protruding from the exterior side while some are built into the fascia of the vehicles so that they seem to follow the contour of the car's body.  In regular door handles, a toothed wheel at the side panel of the door, called a rotor, helps do the job. The rotor rotates and turns its teeth so to latch and unlatch with the striker when you open and close the car door.