A carport is a covered structure used to offer limited protection to vehicles, primarily cars, from rain and snow. 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. In particular, a carport prevents frost on the windshield. A "mobile" and/or "enclosed" carport has the same purpose as a standard carport. However, it may be removed/relocated and is typically framed with tubular steel and may have canvas or vinyl type covering which encloses the complete frame, including walls. It may have an accessible front entry or open entryway not typically attached to any structure or fastened in place by permanent means put held in place by stakes. It is differentiated from a tent by its main purpose: to house vehicles and/or motorized equipment(a tent is to shelter people).