From the ASP.NET site:
ViewBag is a dynamic object, which means you can put whatever you want
in to it; the ViewBag object has no defined properties until you put
something inside it.
The ViewBag.Title property is simply a string object. In this case it’s being used in the view to actually define the Title property. If you were to look in your _Layout.cshtml file you would likely see something like:
<title>@ViewBag.Title</title>
Remember when the property was defined in the view? When the page is finally rendered, that property ends up in the HTML markup looking like:
<title>Store</title>
Which sets the browser title.