There are many names for these types of garden structures that are characterized by columns and an open roof. The structures may range from simple rustic structures to highly detailed and expensive architectural features. As always the design intent, context and site should guide the choice of type.

Shade structures or arbors have existed since Roman times and earlier. The open roof is intended to be the support for vines that can provide both shade and the cooling power of leaves. The classic pergola is a special case of such shade structures that may be consistently characterized by linear form and a flat open roof resting on a colonnade. Such shade structures may be freestanding or attached to the main structure as a kind of porch.

The uses of pergolas, arbors, galleries and other such shade structures are similar to that of pavilions except that the open roof limits their use to rainless hours and the use of vines to cover the roof adds the cooling power, delightful appearance and fragrant smells of flowering vines.