A window space projecting outwards from the main wall of the building, forming a bay in the room perfectly defines what bay windows are like. An example of the same is:

Bay window is the common term that is used for all the protruding windows. The common angles for the bay windows are 90, 135 and 150 degrees but many a time 120 degree angle made by two windows set can also be seen.

All of the bay windows are either polygon or square shaped. A combination of bay window with flat front and angled sides is known as Canted. A bay window which is supported by a bracket, corbel or similar shapes is known as an oriel window.

 

Inside look of a bay window

Outside look of a bay window

Historically, bay windows are associated with English Renaissance of early era. Nowadays, bay windows are a common sight in hotels, resorts, mansions located near sea side to give a pleasant look of the sea or ocean. Natural light and view is the key cause why people want and incorporate bay window. Terrace houses, detached houses, semis as well as in blocks of flats, bay windows are used.