A pergola is an outdoor room with cross rafters and no walls meant to define an outdoor space. It provides a light, airy place to relax or dine. Pergolas are generally freestanding, but can be attached to another building. They work great both within the landscape and next to the home.
A covered patio is a structure that is attached to the house. The design of the house and the roof must usually be taken into consideration (windows and roofline). The covered patio will normally sit below the roofline. How enclosed the patio will be can vary depending on the preference of the homeowner.