After a screen has been set up, a window manager takes control of it. A root window that covers the whole screen area is created as well as a "Topbar Menu". Depending on the settings that have been made within the dialog "Open URL Window", additional windows may be opened automatically too.
The main task of a window manager is to coordinate a varying number of overlapping windows, to interpret incoming events such as key strokes and mouse events, and to deliver them, perhaps after a transformation, to the correct window. Other kinds of events may be sent too, e.g. notifications about focus changes. New windows may be created by applications and open windows may be destroyed, closed, moved, brought to top or pushed behind others.
The window manager also evaluates certain keyboard shortcuts and mouse actions on the root window, e.g. pressing the mouse button on the root window or invoking Alt-M on the keyboard causes the "Main Menu" to appear. Another application is the "Windows Menu", which lists all currently active windows and which may be invoked either by pressing the right mouse button (if available) on the root window or by using the keyboard shortcut Alt-W.
A window is displayed as a rectangular area on the screen and is the main target of the window manager. Almost all windows have a border, called the frame, that is used by the window manager to get a hand on the window, e.g. for moving it. The contents of the inner area of a window is controlled by an application and may be updated at any time.
Every window has a keyboard shortcut associated to it which is used to identify and activate the window. The shortcut is usually shown in the upper left corner within the frame of a window.
Window shortcuts are taken from a predefined range of keys: These keys are the function keys F1 to F10 and their combination with all modifiers, i.e. Shift, Control and Alt, in that order. Any other key may also be used as a shortcut, but this is done only on demand of an application, especially the menues make extensive use of it.
The symbol [X] is usually shown within the upper right corner
of a window frame and indicates that clicking with the mouse into
this area should cause the window to close. Independent of the fact whether
the symbol is really shown or not, this action has the effect that the
corresponding window receives a ^C key event instead, which may
also be used by itself for the same purpose. It is conventionally used to
signal to the application that it should act accordingly and close the
window, but this event may be ignored by an application.
Double clicking with the mouse into the frame area where the
window shortcut, e.g. F2, is normally shown destroys a window
always and unconditionally, independent of the fact whether the shortcut is
actually shown or not. The same effect can be achieved by using the key
combination ^D. Destroying a window should be regarded as the last
resort to close a window, because the affected application has no chance to
hinder this action.
The rest of a window frame is used for other common operations such as (de)activating and/or moving the window. Certain parts of a frame may also be used for informational purposes, e.g. a title is commonly displayed right-aligned at the top.