Quitting from KDE
There are several easy ways to log out from your KDE session:
From the Main Menu -- Select the Logout item (see Figure 4-3).
From the Panel -- Select the Logout icon, which looks like:
From the desktop -- Right-click on the desktop and select Logout from the menu.
Like GNOME, KDE offers you the chance to save your current settings, which will preserve your panel settings and keep your currently open applications.
If you're working in an application and you haven't saved your work when you log out, a dialog will inform you that you'll lose your unsaved material when you log out.
When you see this dialog, you can simply select the Cancel button, save your work, then log out again. If you continue without saving your work, you'll lose the data.