The root view is the view that is loaded when the app is started.
The root view is the view that is loaded when the application is started. For more information, see App Overview: The Basic Files of Your App.
If the standard root views NavContainer or FlexibleColumnLayout don't fit your requirements, you can create and register a custom root view.
For more information and live examples, see the SAP Fiori Development Portal at Custom Page - Custom Root View.
For information about SAP Fiori elements for OData V2, see Using a Custom Root View.