The flying buttress is a specific form of buttress composed of an arch that extends from the upper portion of a wall to a pier of great mass, in order to convey to the ground the lateral forces that push a wall outwards, which are forces that arise from vaulted ceilings of stone and from wind-loading on roofs.
Arching above a side aisle roof, flying buttresses support the main vault of St. Mary's Church, in Lübeck, Germany.
The 4th-century Rotunda of Galerius in Thessaloniki, Greece, showing an early example of flying buttresses
Flying buttress of Reims Cathedral, as drawn by Villard de Honnecourt
Architectural drawing of a Neo-Gothic flying buttress for the late 19th-century Votive Church, in Vienna
An arch is a curved vertical structure spanning an open space underneath it. Arch can either support the load above it or perform a purely decorative role. The arch dates back to fourth millennium BC, but became popular only after its adoption by the Romans in the 4th century BC.
Gateway Arch
A complex funicular model (Church of Colònia Güell by Gaudi, 19th century)
Arcades of Pont du Gard (Roman)
Separating arches in the St. Zeno church [de]