Grips are lighting and rigging technicians in the film and video industries. Grip's two main functions are to work with the camera department (especially regarding dolly and crane shots) and with the electrical department to create lighting set-ups requested by the cinematographer. The name, Grip, comes from the slang term for the tool bag or "grip" in which these technicians carry their tools.
The grip is responsible for handling all of the non-electrical equipment that modifies light. Grip trucks will contain all the supplies necessary to support camera and electrical departments during a production.