A variable or expression contained in a method call and passed to that method. See also "formal parameter".
A method that is run when an object is instantiated, usually to initialize that object's instance variables.
The process of hiding and restricting access to the implementation details of a data structure.
A name, introduced in a method definition, that is replaced by an actual parameter when the method is called.
A method used within the implementation of a class but not used by clients of that class.
The property of an object that it is the same thing at different points in time, even though the values of its attributes might change.