Objects and agents seem to be two different entities, but in the authors' opinion, like objects are successors of modules and agents are successors of objects. In other words, always active objects are agents. The only noticeable difference is that the invocation of the entities: object's invocation is external, i.e. through an external message or though, an external call but agents are "Intelligent" objects, which can be called also but at the same time they possess autonomous property also. They don't need to be evoked externally; rather they can observe the environment around them and can react of their own without any provocation.