The purpose of the Pentaho Design Studio is to facilitate the creation and management of files within your Pentaho solutions. The Design Studio helps organize these files and provides editors for each type of file. There are several levels of organization within the Design Studio: workspaces, project, views, editors, and perspectives. If you haven't done so already start up the design studio and take a look at the basic layout.
A workspace is a directory that contains a collection of projects, along with preferences and other settings related to the projects it contains. When working in the Design Studio keep in mind you are working with a single workspace. If you would like to change the workspace currently being used by the Design Studio simply select the Set Workspace option from the File menu. The Design Studio comes with a preexisting workspace containing a single project called Default Project.