title: MVC4's mapRoute URL -- {controller}/{action} vs Controller/{action}. What's the difference?
body: <p>I recently got burned by the fact that these two MVC4 routes, apparently, function differently. I was wondering if someone could highlight what's going on so I could better understand.</p>
  
  <pre><code>routes.MapRoute(
      "post-User",
      "User",
      new { controller = "User", action = "create" },
      new { httpMethod = new HttpMethodConstraint("POST") }
      );
  
  routes.MapRoute(
      "post-User",
      "{controller}",
      new { controller = "User", action = "create" },
      new { httpMethod = new HttpMethodConstraint("POST") }
      );
  </code></pre>
  
  <p>I thought that the {controller} bit was a placeholder and that saying controller = "User" in the next line would make these two statements equivilant. Apparently using {controller} sets up defaults for all routes?</p>