# Application Parts

These classes provide the top level application GUI functionality, like main window, menu and tool bars, tool tip help etc.

Classes:

- QMainWindow (Typical application window, with a menu bar, some tool bars and a status bar)
- QMenuBar (Horizontal menu bar)
- QStatusBar (Horizontal bar suitable for presenting status messages)
- QToolBar (Simple tool bar)
- QToolTip (Tool tips (sometimes called balloon help) for any widget or rectangular part of a widget)
- QWhatsThis (Simple description of any widget, e.g. answering the question "what's this?")