Within TYPO3 CMS, a workspace is a place where you can author content of a Web site before it is published and visible to site visitors.
Using workspaces, you cannot break a site (unless you publish the change).
A workspace uses the concept of versioning to make this happen.
Versioning means each revision of a page is identified by a version number. In terms of books, think "third edition," for example. One or more authors and reviewers work on the content until they are ready to publish the next edition, or version. The old content is kept on the live site seen by visitors until the new version is published.
This also means that you could delete a page in a site and as long as you don't publish that change, all you have to do is cancel the deletes (this is called Remove from workspace) and visitors won't know anything happened at all. Or you could author a large block of new content and without publishing it, visitors won't know you authored it.
At NDSU, your site is located in a workspace labeled yoursite_draft. Why "_draft?" It's because we call these unpublished versions "drafts." When you edit a page in CMS, a copy is made and you work on the draft copy, never the live version.
It's not as complicated as this sounds. All of the versioning and draft copies are automatically created and managed by TYPO3.
If you have access to more than one workspace, the Workspace selector is visible at the top of the TYPO3 interface.
The active workspace is also displayed at the top of the Pagetree.

A workspace can contain more than one NDSU Web site.
This option is commonly chosen when
For example, if the College of Engineering and Architecture used TYPO3 for the main COA site (hypothetically www.ndsu.edu/cea) there would be a workspace called cea_draft for the site. If the college wanted the same team of people to manage and maintain all of the department sites for the college, they could request for other sites to be added to the workspace. Upon approval from the cea_draft workspace owner, the cea_workspace would contain www.ndsu.edu/coa, Mechanical Engineering www.ndsu.edu/me, Industrial Engineering www.ndsu.edu/ime, Electrical Engineering www.ndsu.edu/ece, etc.