To see it press the mouse MENU button when the pointer is over the dark area of the workspace. This brings a menu of choices. A chosen GUI application loads and becomes active in its own window. A window can be dragged within the workspace, reduced in size or turned into an icon.
Most windows have scroll bars.
Several icons become highlighted and you drag them to the waste basket as it were a single object. Click that button on the window of an active application to get hidden menu. Then click a command from that menu to perform a task. Each application is a program. It exists as an executable file on the hard disk.