How to pass data between controllers and views?

There are several methods.

Examine in detail the concept of MVC and why it is needed. The data needs to go from controller to the view for display and presentation to the controller. No more. No between views and between controllers.
If You want to store common data for all views, then save them either in the session (server side) or cookie (client-side). And index will read this data, such as cookies and display layout.