Java instance variable | an attribute or association | | an interface as its type which means that, with the variable, you can invoke any operation supported by the interface | as private as reasonably possible - almost never make them public | other variables and methods in any class in the same package by default | different classes of objects depending on the type of the variable | The Basics of Java | giving the data type followed by the name of the variable | a particular object, several different objects during the execution of a program, or no object at all | Java variable | private | |