Materials handling refers to the loading, moving, and unloading of materials, often using mechanical equipment or transportation devices. Material handling systems range from conveyors, dollies, and carts, to cranes, hoists, and trucks. Considerations of material size, weight, and fragility determine the appropriate mode of transportation employed in handling. In the industrial sector, the rate at which products or manufacturing supplies can be moved is often a central concern because it affects both costs and production efficiency. In addition, safety is an important factor, especially when handling sensitive or hazardous material.