The Welcome screen is the first screen to appear after login if you have selected "Splash" as your default screen in the Preferences screen. You can use the graphical button (the arrow next to the word "Welcome") to hide and show the navigation area and system area. The arrow points to the left if the navigation area is currently shown, and it points to the right if the navigation area is hidden.
You can use the Welcome screen to navigate to other screens within the system. You can also reach the Desktop and Help About screens.