A pergola can be freestanding or attached to a building. It consists of at least four columns (or two columns and wall for attached designs) that support a latticework made up of beams, rafters and stringers to create a shaded structure perfect near a pool, on a deck or freestanding in an outdoor living space.

The space underneath a pergola can be used to shelter an outdoor living or dining area, an outdoor kitchen or even a cocktail bar. 

A trellis is a piece of latticework that can stand on its own or be attached to a wall, an arbor, a pergola, or gazebo as a place for vines to climb.

An arbor is typically used as an entrance for a garden or walkway. Arbors can be straight or curved on the top and usually have a trellis on two sides.

Gazebos are standalone structures that consist of a raised platform, low walls, columns, and a complete roof. They are typically round or polygon shaped and can include bench seating around the outer edge. Many times, they are positioned away from a home or business to take advantage of views or provide an outdoor escape.