"Plasma Netbook starts much the same as any edition of KDE, with a splashscreen that gradually adds icons as features are loaded. As soon as the desktop appears, though, the differences become noticeable.
"True, at first glance, the panel along the top looks much the same as in standard KDE. It includes a notification tray, calendar, device notifier, and the other widgets that you would expect to see. On the right side of the screen is a button that is the equivalent of the desktop tool kit (popularly known as "the cashew") in standard KDE.
"But on second look, the differences loom large. No menu exists, and what looks like the taskbar, the context menu tells you, is actually an activity bar. In other words, instead of displaying applications, the activity bar lists what KDE developers call "containments" -- workspaces that define how widgets are arranged on the screen. The activity bar is a mechanism for switching between activities."
