A Grip in English (US) is a stage/set technician specializing in rigging of any sort, including scaffolding, dolly operation, camera, lighting, electrical supply. The Grip department head is know as the Key Grip. Mainly Grips work with the camera crew, in particular when the shot calls for a specialized camera mount, e.g. on a Dolly or a Crane shot or some other unusual position that requires rigging. Perhaps a moving car. Secondly Grips support the electrical department in setting up lighting for a shot.