Arches come in a range of shapes which may be round-topped, pointed or square. An arch may be to frame a view or lead the way from the house to the patio, or can highlight the entrance to a pathway or the route beyond a fence or hedge. A row of arches may be lined up along a path.
A pergola is a larger structure made up of a series of joined arches. This may form a single divide between one area of the garden and another bur it is commonly made of a double row of uprights held together by roof struts and placed to span a path or form a covering for a patio. A pergola can also be attached along one side to a wall or fence.