An object is a run-time system element that consists of its own data and shares the methods defined in its class definition. An object is defined by a class. The class definition describes the characteristics of the data and the methods that may be invoked on each of the objects of the class.
Every class also has a single factory object with its own unique set of data and methods. The factory object is typically used to create object instances, and to maintain data common to all instances of the class.