The Xfce panel is part of the Xfce Desktop Environment and features program launchers, panel menus, a clock, a desktop switcher and more. Many aspects of the panel can be configured through graphical dialogs, but also by GTK+ style properties and hidden Xfconf settings.
This manual should provide you with all necessary information on how to adjust the panel to your liking.
Starting the Xfce Panel for the first time
Add New Items
Add new plugins to the Xfce Panel
Configure the Xfce Panel
Styling the Xfce Panel
Log out, lock or other system actions
Show a menu containing categories of installed applications
What time is it?
Show a directory tree in a menu
Program launcher with optional menu
Area where notification icons appear
Adds a separator or space between panel plugins
Hide all windows and show the desktop
Switch between open windows using buttons
Switch between open windows using a menu
Switch between virtual desktops
Debugging plugins and the panel