A casement window is a window that is joined to a frame using one or more hinges. When the window is joined from the side this is called a casement window, windows that are joined from the top are called awning windows or fanlights, windows hinged at the bottom are called hoppers. Casement windows are held open using a casement stay, casement windows are either used singly or in pairs inside a frame and so will be hinged from the outside. However Casement windows in the UK did operate opening inwards, these usually contained leaded glass where the glass panes where held together with stripes of lead called 'cames'. The casement windows are the most common window used on houses before the sash window. Casement windows are also fantastic for ventilation purposes, especially in warm climates. They can be used to direct air flow into the building by opening outwards and being held by casement stays, allowing the window to angle the breeze into the building. Not all windows have to be opening on hinges, in many cases windows are fixed to the frame especially on bay windows where all the windows are not needed to be opening, but still giving a stylish effect to the property and keeping everything in proportion.