A bracket is a structural or decorative architectural element that projects from a wall, usually to carry weight and sometimes to "strengthen an angle".
Brackets vary widely in shape, but a prototypical bracket is the L-shaped metal piece that attaches a shelf (the smaller component) to a wall (the larger component): its vertical arm is fixed to one (usually large) element, and its horizontal arm protrudes outwards and holds another (usually small) element.
Brackets can support many architectural items, including a wall, balcony, parapets, eaves, the spring of an arch, beams, pergola roof, window box, or a shelf.
In adjustable shelving systems, the bracket may be in two parts, with the load-bearing horizontal support fitting into a wall-mounted slotted vertical metal strip.
They can be of cast stone or resin-foam materials with faux finishes for use on new buildings in historic revival styles of architecture.