Object-Orientation FAQ Please visit the new site and make a bookmark to it. This location will go away soon. This is common in the AI domain, where semantic nets use inheritance to understand the world by using classes and concepts for generalization and categorization, by reducing the real-world's inherent complexity.
Inheritance also provides for code and structural reuse.
In the above Computer class diagram, all routines and structure available in class Computer are available to all subclasses throughout the diagram. All attributes available in Personal computers are also available to all of its subclasses. This avoids code redundancy, since code would have to be copied and modified otherwise.