Fundamental concept of object

From object-oriented language such as C++, small-talk and java to architecture such as CORBA, COM, EJB have a object concept as their basic model. Basically, the concept of object currently accepted as architecture things might be defined simply as models of entities or concepts. For example, an object can model an animal, a date, an employee, a particle (whatever), or even a compiler. The important characteristic if an object is its identity, which is fixed for the life of the object regardless of the object is its behavior or properties. This identity is represented by an object reference.

And the concept that helps the object as accessories are the operations and interfaces. An operation is a behavior offered by an object that is known to the outside user. The action of sending request to an object is equivalent to the action of invoking an operation on an object. This operation may cause some changes in the encapsulated state of the object. Generally, interface is a collection of operations offered by that object. The three models mentioned above are same with this definition.

Object itself can be inherited by its behavior. The inheritance concept in object might be come true various ways. Through the inheritance of interface, CORBA and EJB do this. And COM model does this by object aggregation or containment.
Object has life time that can be subjected under its properties or controlled by outer policy. During the incarnated state of object, it can retain its status information or does not possess its data despite of its active state. Depending on this properties object can be divided by state and stateless object. And also, to sustain data out of its lifetime, object can use other repository for its persistency.

As result, including that object a model of entities or concept, four things mentioned above - identity, interfaces, inheritance, lifetime- can be fundamental concept.