You can rename any of your folders and sub-folders so long as you have "Manager" permissions and are not deleting the root folder. You can rename a folder two different ways:
A. Right Click to Rename

The "Folder Properties" dialog opens.

The new name is updated and displayed in the folder structure in your workspace.

B. Double Click to Rename

Once team members synchronize with your workspace, the name will also be updated on their computers.
To learn more about folders, see the Folders FAQ section.