Whenever you use the arrow buttons to hide the panel, the toolbar
displays
buttons to access the main menu, the disk navigator, and the
window list. These buttons will disappear when you show the panel
again.
In the panel settings module of the Control Center, you can adjust the
positioning of the taskbar on the screen or choose not to display it
at all. You can also set it to autohide so that it reduces when you
aren't using it.