Menu is a list of links which the application user sees in the left sidebar.
You can add following menu items: Internal links, External links and Folders.
Internal link (in-app) items are created when you drag and drop items from the Items box in the left part of the Menu Editor.
An External link is a regular link with a fixed URL. It is opened in a new tab.
Folders exist just for grouping menu items.
You can define more than one menu per application. But only one is used as a main app menu. Default menu for the project can be selected on the Settings page.
The first created menu becomes default automatically. You can select a specific menu for a data type in its details page.