A display window, most commonly called shop window (British English) or store window (American English), is a window in a shop displaying items for sale or otherwise designed to attract customers to the store. Usually, the term refers to larger windows in the front façade of the shop. Display windows at boutiques usually have dressed-up mannequins in them.
Putting a window display of merchandise in a store's window is called "window dressing", which is also used to describe the items displayed themselves. As a figure of speech, "window dressing" means something done to make a better impression, and sometimes implies something dishonest or deceptive.