Java Implicit and Explicit parameters

Parameter (explicit parameter): Input to a method. Not all methods have explicit parameters.
System.out.println(greeting) // explicit parameter is greeting
greeting.length() // has no explicit parameter

Implicit parameter: The object on which a method is invoked
System.out.println(greeting) // implicit parameter is System.out

[추가자료] http://java.about.com/od/i/g/implicitparam.htm
[출처] http://akira.ruc.dk/~mir/csa2007s/slide-2-18.html