3. GRAPHICAL COMPONENTSWindows and panesThe display layouts are hierarchically organised. The layouts are built usingcomponents called windows and panes.screen Screen is the topmost display component,corresponding to the entire pixel area of thephysical screen.window Window is a component that has no parent exceptthe screen. Typically a window fills up the entirescreen, but there are also smaller (temporary)windows that take up only a part of the screen,leaving other parts of the screen visible aroundthemselves.Each application runs in a window of it's own.Applications can also use other temporary windows.pane Pane means a sub-component of a window (sub-window).A window may contain many panes, and each panemay contain further sub-panes and so on. A bottomlevel component that cannot have a sub-component, can be called an element.Status paneMain paneControl paneFigure 3-1. Panesapplication window An application window is a principal window fillingup the entire screen. It is usually not used directlyfor display, but just as a parent for the variouspanes.A typical application window is divided into thefollowing panes:11