A carport is a covered structure used to offer limited protection to vehicles, primarily cars, from the elements. The structure can either be free standing or attached to a wall. Unlike most structures a carport does not have four walls, and usually has one or two. Carports offer less protection than garages but allow for more ventilation.
Quoting from the Carport Integrity Policy for the Arizona State Historic Preservation Office:
As early as 1909, carports were used by the Prairie School architect Walter Burley Griffin in his design for the Sloan House in Elmhurst, Illinois (Gebhard, 1991: 110). By 1913, carports were also being employed by other Prairie School architects such as the Minneapolis firm of Purcell, Feick & Elmslie in their design for a residence at Lockwood Lake, Wisconsin. In this instance, the carport was termed an “Auto Space” (Gebhard, 1991: 110). The late architectural historian David Gebhard suggested that the term “carport” originated from the feature’s use in 1930s Streamline Moderne residences (Gebhard, 1991: 107). This term, which entered popular jargon in 1939, stemmed from the visual connection between these streamlined residences and nautical imagery. In the 1930s through the 1950s, carports were also being used by Frank Lloyd Wright in his Usonian Houses; an idea that he probably got from Griffin, a former associate.