Difference between Function and function() Types

Function matches any kind of function, but function() matches only a particular signature. For example, given these functions:

 function Foo (x : int) : float {
     return x/2.0;
 }
 
 function Bar () {
     Debug.Log ("Yo");
 }

Then both of these will work:

 var foo : Function = Foo;
 var foo2 : function(int):float = Foo;

This, however, will not work:

 var bar : function(int):float = Bar;

Because the Bar function doesn't take any arguments and returns void. So it would have to be this instead:

 var bar : function():void = Bar;