The horizontal distance bridged by a structural element such as a beam, truss, or overhead canopy between two support points. Span is a critical structural engineering variable that determines the size, material, and cross-section required to safely carry a given load without excessive deflection or failure. In exhibit and installation design, spans must be engineered appropriately for canopy structures, overhead sign supports, second story decks, and any other element that bridges a horizontal distance between vertical supports.