Racking is defined as a framework, support or stand in or on which to hold, hang, or display various articles. Racks come in all shapes and sizes. A shelf is a type of rack. But there are many other types, some of which look like shelves, while others don't. In everyday life we see bicycle racks in schools and colleges and towns like Amsterdam where many bikes are used. We see different styles of racks in shops to hold and display coats, hats and dresses. In the gym, racks are used to hold weights and weightlifting equipment. In the home, the bathroom will always have a towel rack.

The kitchen will have a rack by the sink for drying plates and dishes, along with racks for wine bottles, spice bottles and salt and pepper cruets. In the lounge, newspapers, magazines and sheet music are often stored in racks. Racking is used for home entertainment systems too. You often see rack holding a DVD player and a satellite TV receiver. But the biggest use of racking by far is in industry for holding a massive range of articles. Like in the home, electronic equipment in industry is often held in racking. In the computer industry for instance, racks are used to hold servers and disc drives. Using a specially designed rack saves installation time and helps to keep cables tucked away neatly. Modular racks of this type facilitate the future addition of new equipment to what's already there. And their vented shelves increase the lifespan of the components mounted inside by allowing proper ventilation so that overheating is avoided. The first stage in deciding the size of this type of rack is simply to add together the height of all of the products to be mounted, and add at least another third again to allow for ventilation and future system expansion.

Some racking can be enclosed with lockable doors. Enclosure enables electronic equipment to work in a controlled environment and prevents interference with the installation from loose objects or prying hands. Enclosed racking also stops valuable or dangerous equipment being removed or tampered with. This is the case with sensitive and valuable electronic equipment and dangerous chemicals. In warehouses we see bulk storage racks which are basically very large shelves. The same applies to document storage racks. Pallet racking often has a wire deck in a metal framework. The wire aids the circulation of air so that stored items can dry out if they were damp when put into storage. Cable reel racking is for storing reels of cable. The reel can rotate on the racking so that lengths of cable can be pulled and cut. Drum pallet racking is for storing oil drums and other similar containers. Like a large-scale wine-bottle rack, each oil drum is supported on two bars around eight inches apart. Cantilever racking has arms that incline upwards.

This type of racking is ideal for storing and displaying rods, pipes, bars, planks and dowels. These types of items can also be stored on stacking racks, which are u-shaped devices that can be attached together in a modular system. Special-purpose racking is used for storing items like gas cylinders. Basically it holds the cylinders steady and stops them falling over.