An arcade is a succession of contiguous arches, with each arch supported by a colonnade of columns or piers. Exterior arcades are designed to provide a sheltered walkway for pedestrians. The walkway may be lined with retail stores. An arcade may feature arches on both sides of the walkway. Alternatively, a blind arcade superimposes arcading against a solid wall. Blind arcades are a feature of Romanesque architecture that influenced Gothic architecture. In the Gothic architectural tradition, the arcade can be located in the interior, in the lowest part of the wall of the nave, supporting the triforium and the clerestory in a cathedral, or on the exterior, in which they are usually part of the walkways that surround the courtyard and cloisters.
Many medieval arcades housed shops or stalls, either in the arcaded space itself, or set into the main wall behind. From this, "arcade" has become a general word for a group of shops in a single building, regardless of the architectural form.