An override redirect window is not under the control of the window manager.
This means it won't have a titlebar, won't be minimizable, etc. - it will
be entirely under the control of the application. The window manager
can't see the override redirect window at all.
Override redirect should only be used for short-lived temporary
windows, such as popup menus. GtkMenu uses an override redirect
window in its implementation, for example.
An override redirect window is not under the control of the window manager. This means it won't have a titlebar, won't be minimizable, etc. - it will be entirely under the control of the application. The window manager can't see the override redirect window at all. Override redirect should only be used for short-lived temporary windows, such as popup menus. GtkMenu uses an override redirect window in its implementation, for example.