A Workspace is the area where you can create, modify, and generally work on documents. Access to a given workspace can be shared between a few (or more) users and groups of users to provide a collaborative work area.

A Section is the area where you publish finished documents in order to make them accessible to a large user base, maybe even make them public to unauthenticated users.

So you can see there are two main philosophical differences between them:

• workspaces have much stricter access restrictions than sections,
• you move a document from a workspace to a section by a publishing process.

Of course all this can be customized by developers in any Nuxeo instance depending on use cases.