The Classbody contains the code that defines the functionality of the class and includes
- member variables and
- methods for the class.
In the "real" world, objects are the entities of which the world is comprised.
Everything that happens in the world is related to the interactions between the objects in the world. Just as atoms combine to form molecules and larger objects, the interacting entities in the world can be thought of as interactions between and among both singular ("atomic") as well as compound ("composed") objects. The real world consists of many, many objects interacting in many ways. While each object may not be overly complex, their myriad of interactions creates the overall complexity
of the natural world. It is this complexity that we wish to capture in our software systems.In an object-oriented software system,objects are entities used to represent or model a particular piece of the system.