Because you enabled boot to the graphical desktop during the final installation configuration in Chapter 1, Getting Started with Raspberry Pi, each time you boot the Pi, the desktop automatically appears. The Pi is now very much like a compact version of your desktop PC, laptop, or even iPad.
The desktop environment is called the lightweight X11 desktop environment (LXDE). It is installed on top of a window manager, which in this case is Openbox. Let's take a quick tour of some important elements of the desktop, and at the same time set up some preferences and options.
The information to follow will provide you with the guidance you need to install a screensaver package and set up a desktop accelerator:
On the left-hand end of the taskbar is the main menu icon. When you click on it, one menu option offered is the ability to shut down. If you click on the shutdown menu selection, the End Session window opens. This allows you to select Logout...