View Bag and View Data

View data: is a dictionary used to store data between View and controller; you need to cast the view data object to its corresponding model in the view to be able to retrieve data from it 

View Bag: is a dynamic property similar in its working to the view data, however it is better it doesn't need to be casted to its corresponding model before using it in the view

Diversity between View Data and View Bag

View Data is a dictionary of objects that is derived from View data Dictionary class and accessible using strings as keys.

View Bag is a dynamic property that takes advantage of the new dynamic features in C# 4.0.

View Data requires typecasting for complex data type and check for null values to avoid error.

View Bag doesn’t require typecasting for complex data type.

View Bag & View Data Example:
Public ActionResult Index ()
{
ViewBag.Name = "xyz";
return View();
}

Public ActionResult Index ()
{
View Data["Name"] = " xyz ";
return View();
}
Calling in View
@ViewBag.Name
@View Data ["Name"]