The Navigation Bar is positioned near the end of the application's header, and typically contains links for user authentication, help, feedback, and other global items.
Navigation Bars are also based on the List component in APEX. However, as of APEX 5.1, you may only have a two-level deep menu.
To change your application's Navigation Bar settings, navigate to Shared Components → User Interface Defaults and then click on the edit icon next to the Desktop User Interface. From here, you can navigate to the Navigation Bar region and change the options listed.