The Project management section of the File menu contains three options:
This option allows you to easily choose which project you wish to work in, and to open, close , or create documents within the chosen project. The interaction depends upon on whether or not a project is open. If there is no project currently open, the Start Working… wizard prompts you to create a new project or open a previously created project. If a project is already open, the wizard prompts you to open or create a new document. See Using Start Working for more information.
Close Project is available only when a project is open. It closes the current project and prompts you save any changes made in the open document since it was last saved.
Change Folder is available only when the project is in Book Folders mode. This option allows you to easily move from working in a document belonging to one book folder to working a document belonging to another book folder. See Choose a Book folder dialog.