The ornamental recessed or flat parts in between the stiles and rails are referred to as panels. Six- or four-panel doors are very frequent, however the number of panels varies greatly. Lite This is a door window or glass pane. It can be made of glass, plastic, or wood. Lite windows are used in doors to allow light into a room while still providing an opening for ventilation. In many cases, these windows are fixed, but they can also be movable if they are made of glass. The term "lite" comes from the Latin word lumen, meaning "light." Lites are commonly found in paneled doors like those used in offices to allow natural light into the space while providing a window through which people can look inside the office when it is needed. These doors are usually constructed with three panels: one that fits within the frame of the door, one that fits within the jamb, and one that fits within the header or ceiling joist. The lite is usually located in the center panel where it provides both illumination and ventilation. Door lites are used to describe any type of window that is found in a door. They can be fixed or movable, single or double-hung, solid or hollow core.