Why object oriented development not only allows reuse

In a wider way we can say that object oriented development not only allows reuse and information sharing within an application, but also, it provide a base for project development in future. As and when there is a requirement of adding new characteristics in the system, they can be added as an expansion of existing basic character. This can be done by using inheritance and that too, without major alteration in the existing code. But be alert that just by using object orientation you never get a license to ensure enhancement and reusability. For ensuring enhancement and reusability you have to have a more general plan of the system. This type of design can be developed only if the system is correctly studied and quality of proposed system is explored.