In object-oriented programming, inheritance is a way to form new classes using classes that have already been defined. DITA and DITA Open Toolkit are structured around the principle of inheritance.
In DITA, child topics or elements inherit attributes from their parents. For example, metadata applied to a section of a DITA file will automatically be applied to topics contained in the section. Inheritance also plays an important role in DITA specialization, which allows you to extend a base topic to match your specific requirements by defining only the differences between it and its base topic; the bulk of the specialized definition is inherited.