Bay windows are made up of three windows, usually, in a wood frame, that projects itself outward from the walls of the building. The customary difference between a bay window and any other type of window is that the center window is larger than the two side windows.
A bow window is a curved bay window, which requires specific measurements and regulations. Bow windows are designed to create space by projecting beyond the exterior wall of the building. Typically bow windows can have more window sections than bay windows