A pergola is a backyard feature creating a shaded walkway, passageway, or relaxing location of vertical posts or pillars that generally support cross-beams and a sturdy open lattice, usually upon which woody vines are trained. As a kind of gazebo, it can also be an extension of a building or serve as protection for an open patio or a link between pavilions. Pergolas are sometimes confused with arbours, and the words are usually utilized alternately. An arbour (or arbor in the united states) is usually regarded as a wooden bench seat with a roof, generally enclosed by lattice panels creating a framework for climbing plants. A pergola, however, is a much bigger and more open structure and does not usually include integral seating.