What is the difference between a French door and a patio door?
A French door is a door with multiple glass panes. They are often installed as a pair or in multiple pairs, where one of the pair may be fixed indefinitely with locks or posts. They are most frequently used at the back of a home leading to a deck, garden or patio. A Patio door is a sliding door made of two large panes of glass set in sashes, with one pane stationary and one operable. The glass in a patio door may extend from top to bottom, or the bottom of the door may include a decorative panel.
