Cranes exist in a variety of forms – each tailored to a specific use. Sizes range from the smallest jib cranes, used inside workshops, to the tallest tower cranes, used for constructing high buildings. Mini-cranes are also used for constructing high buildings, to facilitate constructions by reaching tight spaces. Cranes are commonly employed in the transportation industry for the loading as well as unloading of freight. Cranes in the manufacturing plants are often overhead cranes which move along with beams to assist in lifting. Most of the construction sites are filled with such cranes services which deploy a range of these equipment that are in work. A suspended crane or overhead crane is used mostly inside factories and they can transport very heavy loads. In automated and computer operated warehouses, a stacker crane with a forklift is used.