Industrial robots are mechanical devices which to a certain degree, replicate human motions. They are used whenever there is a need to reduce the danger to a human, provide more strength or accuracy than a human, or when continuous operations are required. Most robots are stationary, but some move throughout the workplace delivering materials and suppliers. Many people think of robots as the humanoid type monster that are seen in science fiction and fantasy movies. While we may someday have the technical ability to produce such a machine, today's robots are actually quite simple devices. Motions that we take for granted-picking up a coin from the table, for instance - are considerably more difficult for a robot. To easily and economically program an industrial robot to perform the same task, many of these variables must be restricted or eliminated. Position, reach, weight, and grasp should remain as consistent as possible so that variations do not result in missing or dropping the object. Most are used for repetitive painting and welding operations, while others, known as pick and place robots, are used to lift and place products into machines and packages.