What is the difference between ActionResult and ViewResult?

• ActionResult is an abstract class while ViewResult derives from the  ActionResult class.  ActionResult has several derived classes like  ViewResult, JsonResult,  FileStreamResult  and  so on.

• ActionResult can be used to exploit polymorphism and dynamism. So if you are returning different types of views dynamically, ActionResult is the best thing. For example in the below code snippet, you can see we have a simple action called DynamicView. Depending on the flag (IsHtmlView) it will either return a ViewResult or JsonResult.

public ActionResult DynamicView()
{
   if (IsHtmlView)
     return View(); // returns simple ViewResult
   else
     return Json(); // returns JsonResult view
}