How does redirect to returnUrl work in Asp.Net MVC5

Question

I\'ve started a new MVC 5 site, using the new Asp.Net Identity with Owin. In my \"account\" controller which has the attribute [Authorize], I have fairly standard actions;

Answer 1

       if (Url.IsLocalUrl(returnUrl))
        {
            return Redirect(returnUrl);
        }
        else
        {
            return RedirectToAction("Index", "Controller");
        }