The document discusses different types of relationships that can exist between classes in object-oriented modeling, including aggregation, inheritance, association, and instantiation. Aggregation represents a part-whole or containment relationship. Inheritance defines a hierarchical relationship where subclasses inherit attributes and behaviors from parent classes. Association defines a symmetric relationship where two classes know of and can communicate with each other.

1. OO Relationships DOEACC B-Level OODBMS 2011 Taher S. 3. Object Oriented Data Model

3. Example of Relationships

10. 2. Inheritance- Generalizations & Specializations

12. Generalization- Types

15. 2. Inheritance – UML Notation