TempData vs ViewData

ASP.NET MVC does not use ViewState in the traditional sense (that of storing the values of controls in the web page). Rather, the values of the controls are posted to a controller method.12 Haz 2015

View state is the method that the ASP.NET page framework uses to preserve page and control values between round trips. When the HTML markup for the page is rendered, the current state of the page and values that must be retained during postback are serialized into base64-encoded strings .

State Management techniques in ASP.Net MVC