The shortcut bar appears along the left edge of the workbench window. It is is always active.
The shortcut bar allows quick access to perspectives that are currently open, as well as providing an easy way to open a new perspective. The shortcut bar also contains the fast views.
Here is what the shortcut bar looks like:
Fast views allow you to minimize and expand a view to quickly hide or access it. When you click on a fast view in the shortcut bar, that view is shown in the current perspective. When you click on another view, click outside the workbench window, or change perspectives, the fast view will no longer appear.
You can create a new fast view by simply dragging the desired view to the shortcut bar.
Here is an example of a fast view, using the Repositories view: