The use of the inheritance to have a structure inherit attributes and methods of classes above it.
One of the key milestones in the period in which the object-relational model was created was the creation of a data
model that closely represented the real world. In this approach, objects were created in which both data and its
relationships were all contained in one place. These data models were becoming a norm to be stored on the web. They
also incorporated support for star schemas within data warehouses. Objects that had similar characteristics were
grouped into classes, where they had a shared structure of attributes and behaviors.
