On Sun, 24 Nov 2013 22:44:19 -0500, wrote:

A garage is closed on all 4 sides when the door is closed. ANy kind
of door. Any kind of closed walls.
A carport has one or more open sides and generally has no door.
A garage is designed to be somewhat weather-tight, while a carport
provides a degree of protection against sun and rain.

....except for a parking garage:

http://www.wired.com/images_blogs/autopia/2011/08/parking-garage.jpg

G