Window

A window is an opening in the wall of a building that allows light to enter a room and people to see out. Modern windows are customarily large glassed-in rectangles or squares. At previous times in history they were merely small oval or square holes in the walls. Very early windows were shielded with hide or cloth stretched over the opening or wooden shutters, or they were filled in with mullioned glass[?] (multiple very small pieces of glass joined together with leading) because the technology to make large sheets of glass did not yet exist. Churches traditionally have stained glass windows. Modern-style floor-to-ceiling windows only became possible after the industrial glass-making[?] process was perfected. Today a window can be made in any shape and size desired.

Modern windows come in many styles. These include:

• Double-hung sash window: the traditional style of window, with two separate pieces which overlap slightly and which slide up and down inside a frame; each movable piece is termed a sash
• Sliding window: with two or more separate pieces that overlap slightly, at least one of which slides sideways within a frame
• Casement window: a window which turns out at an angle, staying fixed along one side, usually opening by a cranked mechanism
• Jalousie window: a window (or door) comprising many slats of glass, which open and close like a Venetian blind, usually by a cranked mechanism
• Clerestory window: a vertical window set in a roof structure or high in a wall, used for daylighting
• Skylight: a flat or sloped window built into a roof structure for daylighting
• Bay window: a multi-panel window, with at least three panels set at different angles to create a protrusion from the wall line
• Picture window: a very large window in a wall, intended to provide an unimpeded view
• Fixed window: a window which cannot be opened

The terms "single-light" or "double-light" (or "'more'-light") refer to the number of glass panes in a window.

The word Window dates back to Old Norse "Wind Eye"; opening to the air.

The beam or arch over the top of a window is known as the lintel or transom.

see also: The window cleaner, Windex.

Radar Window

Window was the WW II British code-name for a system to confuse German radar. It consisted of huge volumes of aluminium foil strips cut to a length corresponding to the radar wave-length which were dropped from aircraft so producing huge numbers of spurious echoes. A modern corresponding technique is called chaff[?].

Other British WW II anti-radar techniques included Mandrel[?], Piperack[?], and Jostle[?], fore-runners of modern ECM[?].

Other meanings: window (computing)